17: Application Online Help

Online Help

Introduction

Online help is the system of providing help files with an application. Online help is usually available from the main menu through a menu group created under a Help category.

In the past, the techniques to provide or program online help were not always easy. The early implementations of help were created in a system called WinHelp. This required using a Rich Text Format (rtf) file and appropriately formatting it. It is possible that, when folks at Microsoft developed WinHelp, they had only Microsoft Word in mind. It was difficult to get the required file ready if you were using another application such as WordPad or WordPerfect. Creating the help file was not enough. Once the file was ready, it had to be added to the application, and appropriately. This back and forth gymnastic could result in negligence.

Practical Learning: Introducing Online Help

In your computer, create a folder named College Park Auto-Parts. If you are using Microsoft Windows, create that folder in your C:\ drive
Save the following image in that folder:

Save the following icons to a folder on your computer or to the College Park Auto-Parts folder:

Start Microsoft Visual Studio
Create a new Windows Forms App named AutoPartsInventory5 that supports .NET 8.0 (Long-Term Support)
In the Solution Explorer, right-click the name of the project and click Manage NuGet Packages...
In the NuGet tab, click Browse
In the combo box, type VisualBasic
In the list, click Microsoft.VisualBasic
In the right list, click Install
In the Preview Changes dialog box, click Apply
In the Solution Explorer, right-click the name of the project -> Add -> New Folder
For the name of the folder, type Models
In the Solution Explorer, right-click Models -> Add -> Class...
For the name of the class, type AutoPart
Click Add

Change the document as follows:

namespace AutoPartsInventory5.Models
{
    internal class AutoPart
    {
        internal long    PartNumber    { get; set; }
        internal int     Year          { get; set; }
        internal string? Make          { get; set; }
        internal string? Model         { get; set; }
        internal string? Category      { get; set; }
        internal string? PartName      { get; set; }
        internal string? PartImage     { get; set; }
        internal double  UnitPrice     { get; set; }
        internal string? PictureNumber { get; set; }
    }
}

In the Solution Explorer, right-click Models -> Add -> Class...
For the name of the class, type Repository
Click Add

Change the document as follows:

using Microsoft.VisualBasic;

namespace AutoPartsInventory5.Models
{
    internal static class Repository
    {
        public static Collection AutoParts { get; set; } = new Collection(); 
    }
}

To start a new form, in the Solution Explorer, right-click the AutoPartsInventory5 project node -> Add -> Form (Windows Forms)...
Set the name to Make
Click Add

Design the form as follows:

College Park Auto-Parts - Make

Control	Text	Name	Other Properties
Label	&Make:
TextBox		txtMake	Modifiers: Internal
Button	&Help	btnHelp
Button	&OK	btnOK	DialogResult: OK
Button	&Cancel	btnCancel	DialogResult: Cancel

To create a new form, on the main menu, click Project -> Add Form (Windows Forms)...
Set the name to Model
Click Add

Design the form as follows:

College Park Auto Parts: Model

Control	Text	Name	Other Properties
Label	&Model:
TextBox		txtModel	Modifiers: Internal
Button	&Help	btnHelp
Button	&OK	btnOK	DialogResult: OK
Button	&Cancel	btnCancel	DialogResult: Cancel

To create a form, in the Solution Explorer, right-click AutoPartsInventory2 -> Add -> Form (Windows Forms)...
Set the name to Category
Click Add

Design the form as follows:

College Park Auto Parts: Category

Control	Text	Name	Other Properties
Label	&Category:
TextBox		txtCategory	Modifiers: Internal
Button	&Help	btnHelp
Button	&OK	btnOK	DialogResult: OK
Button	&Cancel	btnCancel	DialogResult: Cancel

On the main menu, click Project -> Add Form (Windows Forms)...
In the middle list of the Add New Item dialog box, click About Box (Windows Forms)
Set the Name to AboutNewAutoPart
Click Add

Change the values in the form as follows:

Product Name: New Auto Part
Version: 1.0.0.5
Copyright: © 2001-2025
Company Name: College Park Auto-Parts
Description: The New Auto Part form is used to create a new store item to be added to the application.

On the main menu, click Project -> Add Form (Windows Forms)...
Set the Name to AutoPartNew
Click Add
On the Toolbox, click Menus & Toolbars
Still in the Toolbox, click MenuStrip
Click the form
On the form, click Type Here. Type &File
Below File, in the Type Here text box, type New &Make...
Below Make, click Type Here, type New M&odel...
Below Model, click Type Here, type New C&ategory...
Below Category, click Type Here, type -
Below the line, click Type Here, type Sa&ve Auto Part
Below Save Auto Part, click Type Here, type -
Below the line, click Type Here, type &Close
On the right side of File, click Type Here, type &Help Enter
Below Help, click Type Here, type &Presentation
Below Search..., click Type Here, type -
Below the line, click Type Here, type &About New Auto Part...

In the Properties window, change the following characteristics of the menu items:

Menu Text	(Name)	ShortcutKey
&File	miFile
New &Make...	miFileNewMake	Ctrl + Shift + M
New M&odel...	miFileNewModel	Ctrl + Shift + O
New C&ategory...	miFileNewCategory	Ctrl + Shift + G
Sa&ve Auto Part	miFileSaveAutoPart	Ctrl + Shift + S
&Close	miFileClose	Ctrl + Shift + X
&Help	miHelp
&Presentation...	miPresentation	F1
&About New Auto Part...	miHelpAboutNewAutoPart	Ctrl + F12

Design the form as follows:

Control	(Name)	Text	Additional Properties
Label		&Part #:
TextBox	txtPartNumber
Label	lblPictureNumber	...
Picture Box	pbxPartImage		BorderStyle: FixedSingle SizeMode: AutoSize
Label		&Year:
Combo Box	cbxYears		DropDownStyle: DropDownList
Label		&Make:
Combo Box	cbxMakes		DropDownStyle: DropDownList
Label		M&odel
Combo Box	cbxModels		DropDownStyle: DropDownList
Label		Ca&tegory:
Combo Box	cbxCategories		DropDownStyle: DropDownList
Label		Part Na&me:
Text Box	txtPartName		ScrollBars: Vertical Multiline: True
Label		&Unit Price:
Text Box	txtUnitPrice		TextAlign: Right
Label		____________________
Status Strip	ssStatusBar		StatusLabel: Text: Guide (Name): slGuide

On the main menu, click Project -> Add Form (Windows Forms)...
In the middle list of the Add New Item dialog box, click About Box (Windows Forms)
Set the Name to AboutCPAP
Click Add

Change the values in the form as follows:

Product Name: Store Inventory
Version: 1.0.0.5
Copyright: © 2001-2025
Company Name: College Park Auto-Parts
Description: This version of the College Park Auto-Parts application 
was created in Microsoft Visual Studio 2022 (the current version was 
created around February-March 2024). The code is written in C#. Some 
photos and other graphics were used to enhance the aesthetic aspects 
of the application).

In the Solution Explorer, right-click Form1.cs and click Rename
Type StoreInventory (to have StoreInventory.cs) and press Enter three times to accept the name and display the form
From the Components section of the Toolbox, click ImageList and click the form
In the Properties window, click (Name) and type AutoPartsImages
Click the ellipsis button of the Images field
In the Image Collection Editor, click Add
Select each of the icons that you had saved
Click OK
On the Toolbox, click Menus & Toolbars and click MenuStrip
Click the StoreInventory form
On the form, click Type Here. Type &File and press Enter
Below File, in the Type Here text box, type &New Auto Part... and press Enter
Below &New Auto Part..., click Type Here, type - and press Enter
Below the line, click Type Here, type E&xit and press Enter
On the right side of File, click Type Here, type &Help and press Enter
Below Help, click Type Here, type &Contents... and press Enter
Below Contents..., click Type Here, type &Index... and press Enter
Below Index..., type &Search... and press Enter
Below Search..., click Type Here, type - and press Enter
Below the line, click Type Here, type &About College Park Auto-Parts... and press Enter

In the Properties window, change the following characteristics of the menu items:

Menu Text	(Name)	ShortcutKey
&File	miFile
&New Auto Part...	miFileNewAutoPart	Ctrl + N
E&xit	miFileExit	Ctrl + X
&Help	miHelp
&Contents...	miHelpContents	F1
&Index...	miHelpIndex	Ctrl + I
&Search...	miHelpSearch	Ctrl + E
&About New Auto Part...	miHelpAboutCollegeParkAutoParts	Ctrl + F4

Design the form as follows:

Control	(Name)	Text	Other Properties
Label		College Park Auto-Parts	Font: Times New Roman, 20.25pt, style=Bold ForeColor: Blue
Panel			BackColor: Black Height: 2
GroupBox		Part Identification
TreeView	tvwAutoParts		ImageList: AutoPartsImages
GroupBox		Available Parts
ListView	lvwAutoParts		FullRowSelect: True GridLines: True View: Details
Columns	(Name)	Text	TextAlign	Width
	colAvailablePartNumber	Part #
	colAvailablePartName	Part Name/Description		300
	colAvailableUnitPrice	Unit Price	Right	80
GroupBox		Selected Parts
Label		Part #
Label		Part Name
Label		Unit Price
Label		Qty
Label		Sub Total
TextBox	txtPartNumber
TextBox	txtPartName
TextBox	txtUnitPrice		TextAlign: Right
TextBox	txtQuantity		TextAlign: Right
TextBox	txtSubTotal		TextAlign: Right
Button	btnAdd	Add/Select
ListView	lvwSelectedParts		FullRowSelect: True GridLines: True View: Details
Columns	(Name)	Text	TextAlign	Width
	colSelectedPartNumber	Part #		45
	colSelectedPartName	Part Name/Description		274
	colSelectedUnitPrice	Unit Price	Right	58
	colSelectedQuantity	Qty	Right	28
	colSelectedSubTotal	Sub-Total	Right	58
GroupBox	Order Summary
Label		Selected Parts Total:
TextBox	txtSelectedPartsTotal	0.00	TextAlign: Right
Label	Tax Rate:
TextBox	txtTaxRate	7.75	TextAlign: Right
Label		%
Label		Tax Amount:
TextBox	txtTaxAmount		TextAlign: Right
Label		Order Total:
TextBox	txtOrderTotal	0.00	TextAlign: Right
Status Strip	ssStatusBar

Context-Sensitive Help

Context-sensitive help allows the user to get local help on a particular control. You, as the application creator, will decide how you want context-sensitive help to work. In the past, you could make it so that if the user clicked a control and then press Shift+F1, the control that had focus would display a yellow box with a word:

Microsoft Access - Context-Sensitive Help

You also make the yellow box appear with many words:You can still do that but the means to do it have changed. Another technique works only on a dialog. It consists of adding a button with a question mark and then creating the words that would display eventually. When you create this type of dialog box, the user can click the question marked button and click a control. The user can also press Shift+F1. This causes the mouse pointer to be equipped with a question mark. The user can then click a control and a yellow box would appear for that control, providing help:

Help

Context-sensitive help is done in a few steps. To start, to support context-sensitive help, the Form class is equipped with a Boolean property named HelpButton:

public bool HelpButton { get; set; }

If you set this property to true or True, its form is supposed to display a button with a question mark. In reality, you must change the form into a dialog box, which is done by setting both the MaximizeBox and the MinimizeBox properties to true or True.

The Help Provider

To make it easy to provide online help in a Windows Forms application, the .NET Framework provides a control named HelpProvider that is based on a class of the same name:

public class HelpProvider : System.ComponentModel.Component, System.ComponentModel.IExtenderProvider

As is the case for other classes, you can declare a variable of this class and initiaze it. This can be done as follows:

namespace AutoPartsInventory5
{
    public partial class AutoPartNew : Form
    {
        HelpProvider HelpProvider;

        public AutoPartNew()
        {
            InitializeComponent();
        }

        private void AutoPartNew_Load(object sender, EventArgs e)
        {
            HelpProvider = new HelpProvider();
        }
    }
}

To visually provide this controk to your application, in the Components section of the Toolbox, click HelpProvider and click your form. After adding this control to a form, the form and all controls on it receive a new property labeled HelpString On HelpProvider_X. You can then type the desired string in the field of the Properties window for each control that would display context-sensitive help.

Practical Learning: Providing Help

Click the Make.cs [Design] tab to access its form
In the Components section of the Toolbox, click HelpProvider and click the form
In the Properties window, change the (Name) to hpCPAP
Click an unoccupied area of the form to make sure no Windows control is selected

In the Properties window of the form, change the following characteristics:

Form Property	Value
FormBorderStyle	FixedDialog
Text	College Park Auto-Parts - Make
StartPosition	CenterScreen
AcceptButton	btnOK
CancelButton	btnCancel
HelpButton	True
MaximizeBox	False
MinimizeBox	False
ShowInTaskbar	False

On the form, click the text box and buttons, and change the following charactereristics

In the Properties window, change the following characteristics:

Control	HelpString On hpCPAP	PlaceholderText
Make Text Box	Type the name of a vehicle manufacturer (domestic or international)	Manufacturer
Help	Access manufacturer-related help
OK	In the Make text box, type a vehicle manufacturer and click OK
Canel	Click to dismiss any change

Below the form, click hpCPAP to select it and press Ctrl + C to copy
Click the Model.cs [Design] tab to access its form
Press Ctrl + V to paste the help provider
Click an unoccupied area of the form to make sure no Windows control is selected

In the Properties window of the form, change the following characteristics:

Form Property	Value
FormBorderStyle	FixedDialog
Text	College Park Auto-Parts - Model
StartPosition	CenterScreen
AcceptButton	btnOK
CancelButton	btnCancel
HelpButton	True
MaximizeBox	False
MinimizeBox	False
ShowInTaskbar	False

On the Model form, click the text box and buttons, and change the following charactereristics

In the Properties window, change the following characteristics:

Control	HelpString On hpCPAP	PlaceholderText
Model Text Box	Common name of vehicle model, with optional characteristics	Known Vehicle Model
Help	Access model-related help
OK	In the Model text box, type the model set by the vehicle manufacturer. You can also provide more details specific to the model. Then click OK
Cancel	Click to dismiss any change

Below the form, click hpCPAP to select it and press Ctrl + C to copy
Click the Category.cs [Design] tab to access its form
Press Ctrl + V to paste the help provider
Click an unoccupied area of the form to make sure no Windows control is selected

In the Properties window of the form, change the following characteristics:

Form Property	Value
FormBorderStyle	FixedDialog
Text	College Park Auto-Parts - Category
StartPosition	CenterScreen
AcceptButton	btnOK
CancelButton	btnCancel
HelpButton	True
MaximizeBox	False
MinimizeBox	False
ShowInTaskbar	False

On the Category form, click the text box and buttons, and change the following charactereristics

In the Properties window, change the following characteristics:

Control	HelpString On hpCPAP	PlaceholderText
Category Text Box	Common or easily recognizable classification of an auto part (can include main or sub-categories of a part).	Classification of a Store Item
Help	Access category-related help
OK	In the Category text box, enter a few word that reoresent (or can briefly describe) the type of item. Then click OK
Cancel	Click to dismiss any change

Below the form, click hpCPAP to select it and press Ctrl + C to copy
Click the AutoPartNew.cs [Design] tab to access its form
Press Ctrl + V to paste the help provider
Click an unoccupied area of the form to make sure no Windows control is selected

In the Properties window of the form, change the following characteristics:

Form Property	Value
Text	College Park Auto-Parts - New Auto-Part
StartPosition	CenterScreen
HelpButton	True
MaximizeBox	False
MinimizeBox	False
ShowInTaskbar	False

On the New Auto-Part form, click some controls and, in the Properties window, change the following charactereristics:

Control	HelpString On hpCPAP	PlaceholderText
Part # Text Box	The part number is required. This number must be unique among the other part numbers of the inventory (every auto-part must have a unique part number).	Unique Part Number
Picture Box	A picture box shows a photo of the auto-part.
Years Combo Box	Vehicle Year: This is the official year the car was released by the manufacturer (not the year the part was made)
Makes Combo box	The vehicle manufacturer, commonly referred to as Make.
Models Combo box	The model of the vehicle. The commonly-known name is from the manufacturer. The model can also include a short description and/or characteristics that make it easy to locate an auto-part.
Category Combo Box	Part Category: This is a name (or a relatively short description) of the type of part.
Part Name Text Box	The name of the auto-part: The name can consist of a few words or a relatively short description with enough information to provide all necessary details.
Unit Price Text Box	This is the current marked price of the auto-part. It doesn't reflect a discount nor a tax amount.	Part Price

HTML Help

Introduction

The online help we described earlier provides only small yellow boxes. It is called context-sensitive help because it provides its assistance on only a control of the form. Another technique, in fact highly supported with any commercial program, consists of providing an external application that resembles an electronic book. This allows the user to get more detailed information about almost any aspect of the application.

The most common way to provide online help is by using a Web site. You can create a local Web site that resides on your computer; that website is accessed only by the computer where the site resides. You can also create a Website that is accessed in the Internet.

Practical Learning: Creating HTML Help Files

Using Windows Explorer or My Computer, create a folder named cpap
Inside of the cic folder, create a folder named images
Inside of the cic folder, create another folder named styles

Save the following images in the cpap\images folder:

College Park Auto-Parts - Accessories

College Park Auto-Parts - New Auto Part

College Park Auto-Parts

Start a text editor, such as Notepad, and paste the content of the cpap.css file in it
Save the file as cpap.css in the styles folder you created
Start another file with the contents of the Accessies document
Save the file as Accessories.htm
Start another file with the contents of the Description document
Save the file as Description.htm
Start another file with the contents of the New Auto Part document
Save the file as NewAutoPart.htm
Start another file with the contents of the Introduction document
Save it as Introduction.htm
Start another file with the contents of the Make document
Save the file as Make.htm
Start another file with the contents of the Model document
Save the file as Model.htm
Start another file with the contents of the Category document
Save the file as Category.htm
Start another file with the contents of the Index document
Save it as index.htm

Introduction to HTML Help

When it comes to online help, a solution that Microsoft made available in the past was called HTML Help. It was an external applicatton that was used to gather existing Web files and make them into an executable application. This means that you had to first create all the files you would need for a website. Once you had the Web files you wanted, you had to start the HTML Help application, create a project, import the necessary files, and make the whole combination into a functioning system. At any time, you could compile the project to create an executable application, which had a .chm extension.

Practical Learning: Introducing HTML Help

If you haven't done so, install HTML Help or www.helpandmanual.com/downloads_mscomp.html or web.archive.org/web/20210126113408/https://www.microsoft.com/en-us/download/details.aspx?id=21138
Start HTML Help Workshop
On the main menu of HTML Help Workshop, click File -> New
In the New dialog box, make sure Project is selected and click OK
In the first page of the New Project wizard, click Next
In the second page of the wizard, click Browse
Locate the cpap folder you created and display its contents
Set the File Name to College Park Auto-Parts
Click Open
In the second page, click Next
In the third page, read the text. Click the HTML files (.htm) check box:
Click Next
In the fourth page, click Add
In the Open dialog box, click the top Web file
Press and hold Shift
Click the last Web file to select them all
Release Shift:
Click Open:
In the fourth page, click Next
In the last page of the wizard, click Finish:
To create the help file, click the Save All Files And Compile button
Inside the HTML Help Worskop, close the window titled Log1
If you want, access the cpap folder and double-click the College Park Auto-Parts.chm executable to see the application
If you had opened that Help application, close it

A Window to Display Help

An HTML Help application primarily appears as a single document or a Web page. In reality, most help systems use many Web files. If you want to display the various HTML files that your system offers, the HTML Help Workshop suggests that you create one or more special windows from which the user can navigate from one Web page to another.

To create a window to display Help, in the Projects tab, you can click the Add/Modify Window Definitions button. Because you are allowed to have many Help windows, to start, you must provide a name for your new window. You can then specify its characteristics, and then modify them later as you wish.

Practical Learning: Creating a Help Window

Click the Add/Modify Window Definitions button
Set the name to MainWnd
Press Enter
Set the Title Bar Text to College Park Auto-Parts
Click the Buttons tab
Click the Home and the Locate check boxes
Click the Position tab
Set the Width to 1920
Set the Height to 1080
Click the Files tab
Click the arrow of the Default combo box and select index.htm
Click the arrow of the Home combo box and select Introduction
Click OK
To create the help file, click the Save All Files And Compile button
Inside the HTML Help Worskop, close the window titled Log1
If you want, access the cpap folder and double-click the College Park Auto-Parts.chm executable to see the application.
If you had opened that Help application, close it

A Table of Contents

To provide the functionality of an electronic book, you can equip your HTML Help application with a Table of Contents section. To start, in your HTML Help Workshop application, create a Table of Contents from the Contents tab.

To support the Table of Contents of HTML Help, the HelpNavigator enumeration has a member named TableOfContents.

Practical Learning: Creating a Table of Contents

In the HTML Help Workshop, click the Contents tab
In the dialog box that displays, read the text in the dialog box. Make sure the first radio button is selected:
Click OK
In the Save As dialog box, accept the suggested name:
Click Save
Click the Insert a Heading button
In the Table Of Contents Entry dialog box, in the Entry Title text box, type College Park Auto-Parts
Click Add
In the Path Or URL dialog box, click College Park Auto-Parts - Home
Click OK
Click OK
Click the Insert A Page button
In the message box that displays, read it and click No
In the Entry Title text box, type Introduction
Click Add
In the Path Or URL dialog box, click Introduction
Click OK
In the Table Of Contents Entry dialog box, click OK
Click the Insert A Page button
In the Entry Title text box, type Description
Click Add
In the Path Or URL dialog box, click Description
Click OK
In the Table Of Contents Entry dialog box, click OK
Click the Project tab
In the list box, below [WINDOWS], double-click MainWnd = "College Park Autp-Parts"
In the Window Types dialog box, click the Files tab
Click the arrow of the TOC combo box and select Table of Contents.hhc
Click OK
To create the help file, click the Save All Files And Compile button
Inside the HTML Help Worskop, close the window titled Log2
If you want, access the cpap folder and double-click the College Park Auto-Parts.chm executable to see the application.
If you had opened that Help application, close it

Help Index

When it comes to a book, an index is a list of special or difficult words for which a reader may need clarifying information. To make your Help project very userful, the HTML Help Workshop allows you to create an index for your Help system.

To create an index, in the HTML Help Workshop, click the Index tab,

Practical Learning: Creating an Index

In the HTML Help Workshop, click the Index tab. Read the content of the dialog box that comes up.
Make sure the top radio button is selected
Click OK
Accept the suggested name of the file and press Enter
Click the Insert A Keyword button
In the Keyword text box, type domestic
Click Add
In the Path Or URL dialog box, click Introduction
Click OK
In the Index Entry dialog box, click OK
Once again, click the Insert A Keyword
You will receive a message box, click one of the buttons Yes or No (it doesn't matter which one)
In the Keyword text box, type tree view
Click the Add or the Edit button (it doesn't matter which one)
In the HTML Titles list box, click Description
At the end of the string in the File or URL text box, add #cpap
Click OK
In the Index Entry dialog box, click OK

In the same way, create new keywords using the following table (sometimes you may receive a message box asking whether you want to create the keyword above the other; for this exercise, it doesn't matter what Yes or No button you click):

New Keyword	Page or URL
appearance	Accessories
accessories	Accessories
security	Accessories
environment	Accessories
warranty	Introduction
company	Introduction
text box	Description.htm#cpap
record	Description.htm#cpap

Click the Sort Keywords Alphabetically button
Click the Project tab
In the list box, below [WINDOWS], double-click MainWnd = "College Park Autp-Parts"
Click Navigation Pane
Click the Window With Navigation Pane, Topic Pane, And Button check box
Click the Search Tab and the Advanced check boxes
Click the Files tab
Click the arrow of the Index combo box and select Index.hhk
Click OK
When the Resolve Window Definition wizard comes up, in the Window Type combo box, make sure the window defined previously is selected.
Click Next
Click Next
Click Finish
To create the help file, click the Save All Files And Compile button
Inside the HTML Help Worskop, close the window titled LogX.
Access the cpap folder and double-click the College Park Auto-Parts.chm executable to see the application
Expand the College Park Auto-Parts node and click Description
If you had opened that Help application, close it
Click the Index tab
Close the Help application and return to your HTML Help Workshop project

Context-Sensitive Pop-up Help

When using your application, the user may open different objects and use some Windows controls. Context-sensitive help is help that applies to a particular object on an application.

Creating or implementing context-sensitive help can involve a few steps so much that it is an option you can avoid in your application (or you can create it if you judge it necessary (and/or helpful)).

The primary object involved with context-sensitive help is a header file. A header file is a C/C++ text fix that has the extention.h. In the document, you create what are called help topics or topic IDs. You can create one or more of such topics. The formula to create a topic ID is:

#define identifier natural-number

The line starts with #define followed by an empty space. This is followed by a name. By tradition, you should (maybe must) start that name with IDH_ followed by one or more digits and leters of your choice. You can also use one or more underscores. By tradition also, the whole name is in uppercase (this is not a requirement). After that name, create an empty space. Add a natural number. If you want to create another topic ID, do it on the next line. In the same way, you can create as many topic IDs as you want. If you are creating more than one topic ID, it is a good idea for each number to be unique.

If you started the document in a text editor such as Notepad, make sure you save it with the .h extension in your HTML Help project folder. After creating the header file, you must import it in your HEML Help project. You must also create a section named ALIAS included in square brackets. Below its line, create an entry for each topic ID. The formula for each topic ID is:

identifier = associated-file

Start the line with an identifier you had created in the header file. Assign a name of a file to the identifier. This is the name of the file that will be associated to the topic ID. After doing this, you should (must) add the

Practical Learning: Creating a Header File

Start a text editor such as Notepad

Type the following lines:

#define IDH_MAKE	  1000
#define IDH_MODEL	  1010
#define IDH_CATEGORY	  1020
#define IDH_NEW_AUTO_PART 1040

Save the file as cpap.h in the cpap folder of your HTML Help project
Return to the HTML Help Workshop.
Click the HtmlHelp API information button
In the HtmlHelp API Information dialog box, click Header File
In the Include File dialog box, click Browse...
Select the cpap.h file from your HTML Help project folder
Click Open
In the Include File dialog box, click OK
In the HtmlHelp API Information dialog box, click OK
To save, click the Save All Files And Compile button
Inside the HTML Help Worskop, close the window titled Log3
Return to your HTML Help project folder.
Right-click the College Park Auto-Parts.hhp file and choose the option to open it in a text file

In the document, create an ALIAS section follows:

[OPTIONS]
Compatibility=1.1 or later
Compiled file=College Park Auto-Parts.chm
Default Window=MainWnd
Default topic=Accessories.htm
Display compile progress=No
Language=0x409 English (United States)

[WINDOWS]
MainWnd="College Park Auto-Parts",,,"index.htm","Introduction.htm",,,,,0x2000,,0x3846,[0,0,1920,1080],,,,,,,0


[FILES]
Accessories.htm
Category.htm
Description.htm
index.htm
Introduction.htm
Make.htm
Model.htm
NewAutoPart.htm

[ALIAS]
IDH_CATEGORY=Category.htm
IDH_MAKE=Make.htm
IDH_MODEL=Model.htm
IDH_NEW_AUTO_PART=NewAutoPart.htm

[MAP]
#include cpap.h

[INFOTYPES]

Close the file
When asked whether you want to save the file, press Enter (or click OK or Yes)

An HTML Provider

Introduction

After creating the HTML Help application, you can use a HelpProvider control to connect it to your application. To start, the HelpProvider class is equipped with a property called HelpNamespace:

public virtual string? HelpNamespace { get; set; }

This property allows you to specify the application that contains the HTML Help application. You can do this by assigning the name or path of your CHM application. Here is an example:

namespace AutoPartsInventory5
{
    public partial class AutoPartNew : Form
    {
        HelpProvider HelpProvider;

        public AutoPartNew()
        {
            InitializeComponent();
        }

        private void AutoPartNew_Load(object sender, EventArgs e)
        {
            HelpProvider = new HelpProvider();

            HelpProvider.HelpNamespace = "C:\\cpap\\College Park Auto-Parts.chm";
        }
    }
}

Besides the HelpNamespace property, the HelpProvider control provides various methods to manage help.

To support HTML Help for a Windows Forms Application, the .NET Framework provides a static class named Help:

public static class Help

Help is a small class that has only three methods, no constructors, and no properties. One of the methods of the Help class is named ShowHelp. It is overloaded in four versions. The simplest version uses the following syntax:

public static void ShowHelp(System.Windows.Forms.Control? parent, string? url);

This version of the ShowHelp() method allows you to specify the help file aplied to a control. The control is passed as the first argument. That control is usually a form. If you call this method on the form that needs the HTML Help file, you can pass the first argument as the this object. The second argument is the help file specified in the HelpProvider.HelpNamespace property already mentioned.

A Table of Contents

An HTML Help application usually displays various tabs. To display the Contents tab of HTML Help, simply call the Help.ShowHelp() method that uses the above syntax. Here is an example:

namespace AutoPartsInventory5
{
    public partial class AutoPartNew : Form
    {
        HelpProvider ? hpAutoParts;

        public AutoPartNew()
        {
            InitializeComponent();
        }

        private void AutoPartNew_Load(object sender, EventArgs e)
        {
            hpAutoParts = new HelpProvider();

            hpAutoParts.HelpNamespace = "C:\\cpap\\College Park Auto-Parts.chm";
        }

        private void miHelpContents_Click(object sender, EventArgs e)
        {
            Help.ShowHelp(this, "C:\\cpap\\College Park Auto-Parts.chm");
        }
    }
}

An Index for HTML Help

To let you access the Index tab of HTML Help, the Help class is equipped with a method named ShowHelpIndex method can be used to open the Index tab of the HTML Help window.

public static void ShowHelpIndex(System.Windows.Forms.Control? parent, string? url);

This method takes two arguments. The first argument is the control that needs the Helps project. Normally, this is a form and it is usually passed as this. The second argument is the CHM file of your HTML Help project. Here is an example of calling this method:

namespace ÂutoPartsInventory1
{
    public partial class StoreInventory : Form
    {
        HelpProvider? hpAutoParts;

        public StoreInventory()
        {
            InitializeComponent();
        }

        private void StoreInventory_Load(object sender, EventArgs e)
        {
            hpAutoParts = new HelpProvider();
            hpAutoParts.HelpNamespace = "C:\\cpap\\College Park Auto-Parts.chm";
        }

        private void miHelpContents_Click(object sender, EventArgs e)
        {
            Help.ShowHelpIndex(this, hpAutoParts!.HelpNamespace);
        }
    }
}

To support the tabs of HTML Help, the .NET Framework provides an enumeration named HelpNavigator.

Based on this, the second and the fourth versions of the ShowHelp() method allow you to specify the tab of the HTML Help window to display when the method is called. This is done through the HelpNavigator enumeration. To let you specify a tab, the Help.ShowHelpIndex() method has another version whose syntax is:

public static void ShowHelp(System.Windows.Forms.Control? parent,
                            string? url,
                            System.Windows.Forms.HelpNavigator navigator);

Using another solution to display the Contents tab of an HTML Help application, the HelpNavigator enumeration has a member named TableOfContents. To display the Contents tab of an HTML Help application, you can pass this member as the third argument. Here is an example:

namespace ÂutoPartsInventory1
{
    public partial class StoreInventory : Form
    {
        HelpProvider? hpAutoParts;

        public StoreInventory()
        {
            InitializeComponent();
        }

        private void StoreInventory_Load(object sender, EventArgs e)
        {
            hpAutoParts = new HelpProvider();
            hpAutoParts.HelpNamespace = "C:\\cpap\\College Park Auto-Parts.chm";
        }

        private void miHelpContents_Click(object sender, EventArgs e)
        {
            Help.ShowHelp(this, hpAutoParts!.HelpNamespace, HelpNavigator.TableOfContents);
        }
    }
}

Finding Help

The third version of the ShowHelp() method can be used to open a help file based on a keyword.

Practical Learning: Providing Online Help to an Application

Click the Make.cs [Design] tab to access its form
Below the Make form, click hpCPAP to access it
In the Properties window, click the ellipsis button of the HelpNamespace property
Locate and display the cpap folder in which you created the HTML Help project. Select the College Park Auto-Parts.chm file
Click Open
In the Make form, double-click the Help button to generate its Click event

Implement the event as follows:

namespace AutoPartsInventory5
{
    public partial class Make : Form
    {
        public Make()
        {
            InitializeComponent();
        }

        private void btnHelp_Click(object sender, EventArgs e)
        {
            Help.ShowHelp(this, hpCPAP.HelpNamespace, HelpNavigator.TopicId, "1000");
        }
    }
}

Click the Model.cs [Design] tab to access its form
In the Make form, double-click the Help button to generate its Click event

Change the event as follows:

namespace AutoPartsInventory5
{
    public partial class Model : Form
    {
        public Model()
        {
            InitializeComponent();
        }

        private void btnHelp_Click(object sender, EventArgs e)
        {
            Help.ShowHelp(this, hpCPAP.HelpNamespace, HelpNavigator.TopicId, "1010");
        }
    }
}

Click the Category.cs [Design] tab to access its form
In the Make form, double-click the Help button

Define the event as follows:

namespace AutoPartsInventory5
{
    public partial class Category : Form
    {
        public Category()
        {
            InitializeComponent();
        }

        private void btnHelp_Click(object sender, EventArgs e)
        {
            Help.ShowHelp(this, hpCPAP.HelpNamespace, HelpNavigator.TopicId, "1020");
        }
    }
}

Click the NewAutoPart.cs [Design] tab to access its form
Double-click an unoccupied area of the form to generate its Load event
Return to the NewAutoPart.cs form and, on the form, click the Part Number text box to give it focus
In the Properties window, click the Events button
In the Events section of the Properties window, double-click Leave
Return to the NewAutoPart.cs form. In the menu in the top section, click File and double-click New Make
Return to the NewAutoPart.cs form and double-click the Make combo box to generate its SelectedIndexChanged event
Return to the NewAutoPart.cs form. In the menu in the top section, click File and double-click New M&odel...
Return to the NewAutoPart.cs form. In the menu in the top section, click File and double-click New C&ategory...
Return to the NewAutoPart.cs form. In the menu in the top section, click Help and double-click Presentation...
Return to the NewAutoPart.cs form. In the menu in the top section, click Help and double-click About New Auto Part...
Return to the NewAutoPart.cs form. In the menu in the top section, click File and double-click Sa&ve Auto-Part
Return to the NewAutoPart.cs form. In the menu in the top section, click File and double-click Close

Change the document as follows:

using AutoPartsInventory5.Models;

namespace AutoPartsInventory5
{
    public partial class AutoPartNew : Form
    {
        public AutoPartNew()
        {
            InitializeComponent();
        }

        private void InitializeAutoParts()
        {
            for (int year = 2025; year >= 2000; year--)
            {
                cbxYears.Items.Add(year);
            }

            if (Repository.AutoParts.Count > 0)
            {
                Random rndNumber = new();

                cbxMakes.Items.Clear();
                cbxModels.Items.Clear();
                cbxCategories.Items.Clear();
                txtPartName.Text = string.Empty;
                txtUnitPrice.Text = string.Empty;
                txtPartNumber.Text = rndNumber.Next(100000, 999999).ToString();

                foreach (AutoPart part in Repository.AutoParts)
                {
                    if (!cbxMakes.Items.Contains(part.Make))
                    {
                        cbxMakes.Items.Add(part.Make!);
                    }
                }

                foreach (AutoPart part in Repository.AutoParts)
                {
                    if (!cbxCategories.Items.Contains(part.Category))
                    {
                        cbxCategories.Items.Add(part.Category!);
                    }
                }
            }

            lblPictureNumber.Text = ".";
            pbxPartImage.Image = Image.FromFile(@"E:\College Park Auto-Parts\Generic.png");

            Width = pbxPartImage.Right + 40;
            Height = pbxPartImage.Bottom + 75;
        }

        private void AutoPartNew_Load(object sender, EventArgs e)
        {
            InitializeAutoParts();
        }

        private void txtPartNumber_Leave(object sender, EventArgs e)
        {
            if (string.IsNullOrEmpty(txtPartNumber.Text))
            {
                return;
            }

            lblPictureNumber.Text = txtPartNumber.Text;
            pbxPartImage.Image = Image.FromFile(@"E:\College Park Auto-Parts\" + txtPartNumber.Text + ".png");

            Width = pbxPartImage.Right + 40;
            Height = pbxPartImage.Bottom + 75;
        }

        private void miFileNewMake_Click(object sender, EventArgs e)
        {
            Make editor = new Make();

            if (editor.ShowDialog() == DialogResult.OK)
            {
                if (editor.txtMake.Text.Length > 0)
                {
                    string strMake = editor.txtMake.Text;

                    if (cbxMakes.Items.Contains(strMake))
                    {
                        MessageBox.Show(strMake + " is already in the list.",
                                        "College Park Auto-Parts",
                                        MessageBoxButtons.OK, MessageBoxIcon.Information);
                    }
                    else
                    {
                        cbxMakes.Items.Add(strMake);
                    }

                    cbxMakes.Text = strMake;
                }
            }
        }

        private void cbxMakes_SelectedIndexChanged(object sender, EventArgs e)
        {
            cbxModels.Text = "";
            cbxModels.Items.Clear();

            foreach (AutoPart part in Repository.AutoParts)
            {
                if (part.Make == cbxMakes.Text)
                {
                    if (!cbxModels.Items.Contains(part.Model))
                    {
                        cbxModels.Items.Add(part.Model!);
                    }
                }
            }
        }

        private void miFileNewModel_Click(object sender, EventArgs e)
        {
            Model editor = new();

            if (editor.ShowDialog() == DialogResult.OK)
            {
                if (editor.txtModel.Text.Length > 0)
                {
                    string strModel = editor.txtModel.Text;

                    if (cbxModels.Items.Contains(strModel))
                    {
                        MessageBox.Show(strModel + " is already in the list.",
                                        "College Park Auto-Parts",
                                        MessageBoxButtons.OK, MessageBoxIcon.Information);
                    }

                    else
                    {
                        cbxModels.Items.Add(strModel);
                    }

                    cbxModels.Text = strModel;
                }
            }
        }

        private void miFileNewCategory_Click(object sender, EventArgs e)
        {
            var editor = new Category();

            if (editor.ShowDialog() == DialogResult.OK)
            {
                if (editor.txtCategory.Text.Length > 0)
                {
                    string strCategory = editor.txtCategory.Text;

                    if (cbxCategories.Items.Contains(strCategory))
                    {
                        MessageBox.Show(strCategory + " is already in the list.",
                                        "College Park Auto-Parts",
                                        MessageBoxButtons.OK, MessageBoxIcon.Information);
                    }

                    else
                    {
                        cbxCategories.Items.Add(strCategory);
                    }

                    cbxCategories.Text = strCategory;
                }
            }
        }

        private void miPresentation_Click(object sender, EventArgs e)
        {
            Help.ShowHelp(this, hpCPAP.HelpNamespace, HelpNavigator.TopicId, "1040");
        }

        private void miHelpAboutNewAutoPart_Click(object sender, EventArgs e)
        {
            AboutNewAutoPart ana = new();

            ana.ShowDialog();
        }

        private void miFileSaveAutoPart_Click(object sender, EventArgs e)
        {
            if (string.IsNullOrEmpty(cbxYears.Text))
            {
                MessageBox.Show("You must specify the year.",
                                "College Park Auto-Parts",
                                MessageBoxButtons.OK, MessageBoxIcon.Information);
                return;
            }

            // Make sure the user had selected a make
            if (string.IsNullOrEmpty(cbxMakes.Text))
            {
                MessageBox.Show("You must specify the car name.",
                                "College Park Auto-Parts",
                                MessageBoxButtons.OK, MessageBoxIcon.Information);
                return;
            }

            // Make sure the user had selected a model
            if (string.IsNullOrEmpty(cbxModels.Text))
            {
                MessageBox.Show("You must specify the model of the car.",
                                "College Park Auto-Parts",
                                MessageBoxButtons.OK, MessageBoxIcon.Information);
                return;
            }

            // Make sure the user had entered a name/description
            if (string.IsNullOrEmpty(txtPartName.Text))
            {
                MessageBox.Show("You must enter the name (or a " +
                                "short description) for the part.",
                                "College Park Auto-Parts",
                                MessageBoxButtons.OK, MessageBoxIcon.Information);
                txtPartName.Focus();
                return;
            }

            // Make sure the user had typed a price for the item
            if (string.IsNullOrEmpty(txtUnitPrice.Text))
            {
                MessageBox.Show("You must enter the price of the item.",
                                "College Park Auto-Parts",
                                MessageBoxButtons.OK, MessageBoxIcon.Information);
                txtUnitPrice.Focus();
                return;
            }

            AutoPart part = new AutoPart();

            part.PartNumber = long.Parse(txtPartNumber.Text);
            part.Year = int.Parse(cbxYears.Text);
            part.Make = cbxMakes.Text;
            part.Model = cbxModels.Text;
            part.Category = cbxCategories.Text;
            part.PartName = txtPartName.Text;
            part.UnitPrice = double.Parse(txtUnitPrice.Text);
            part.PictureNumber = lblPictureNumber.Text;

            Repository.AutoParts.Add(part);

            InitializeAutoParts();
        }

        private void miFileClose_Click(object sender, EventArgs e)
        {
            Close();
        }
    }
}

Return to the NewAutoPart.cs form. Below the NewAutoPart form, click hpCPAP to select it and press Ctrl + C to copy
Click the StoreInventory.cs [Design] tab to access its form
Press Ctrl + V to paste the help provider
Double-click an unoccupied area of the form to generate its load event
Return to the StoreInventory.cs form and, in the Properties window, click the Events button
On the form, click the Part Identification tree view
In the Events section of the Properties window, double-click NodeMouseClick
Return to the StoreInventory.cs form. In its top section, click File and double-click New Au&to Part...
Return to the StoreInventory.cs form. On the form, click the Available Parts list view to select it and, in the Events section Properties window, double-click ItemSelectionChanged
Return to the StoreInventory.cs form and make sure the Available Parts list view is still selected.
In the Events section of the Properties, double-click DoubleClick
Return to the StoreInventory.cs form and click the Part # text box to select it
In the Events section of the Properties window, double-click Leave
Return to the StoreInventory.cs form and click the Unit Price text box to select it
In the Events section of the Properties window, double-click Leave
Return to the StoreInventory.cs form and click the Qty text box to select it
In the Events section of the Properties window, click the arrow of the Leave combo box and select txtUnitPrice_Leave
Return to the StoreInventory.cs form and double-click the Add/Select
Return to the StoreInventory.cs form and click the Selected Parts list view to select it
In the Events section of the Properties window, double-click DoubleClick
Return to the StoreInventory.cs form. In its top section, click Help and double-click Contents...
Return to the StoreInventory.cs form. In its top section, click Help and double-click Index...
Return to the StoreInventory.cs form. In its top section, click Help and double-click About... College Park Auto-Parts...
Return to the StoreInventory.cs form. In its top section, click File and double-click Exit

Change the document as follows:

using AutoPartsInventory5.Models;
using Microsoft.VisualBasic;

namespace AutoPartsInventory5
{
    public partial class StoreInventory : Form
    {
        public StoreInventory()
        {
            InitializeComponent();
        }

        void InitializeAutoParts()
        {
            tvwAutoParts.Nodes.Clear();
            TreeNode nodRoot = tvwAutoParts.Nodes.Add("College Park Auto-Parts",
                                                      "College Park Auto-Parts", 0, 1);

            for (int years = 2025; years >= 2000; years--)
            {
                nodRoot.Nodes.Add(years.ToString(), years.ToString(), 2, 3);
            }

            tvwAutoParts.SelectedNode = nodRoot;

            tvwAutoParts.ExpandAll();

            if (Repository.AutoParts.Count > 0)
            {
                foreach (TreeNode nodYear in nodRoot.Nodes)
                {
                    Collection lstMakes = new();

                    foreach (AutoPart part in Repository.AutoParts)
                    {
                        if (nodYear.Text == part.Year.ToString())
                        {
                            if (!lstMakes.Contains(part.Make!))
                            {
                                lstMakes.Add(part.Make!, part.Make!);
                            }
                        }
                    }

                    foreach (string strMake in lstMakes)
                    {
                        nodYear.Nodes.Add(strMake, strMake, 4, 5);
                    }
                }

                foreach (TreeNode nodYear in nodRoot.Nodes)
                {
                    foreach (TreeNode nodMake in nodYear.Nodes)
                    {
                        Collection lstModels = new();

                        foreach (AutoPart part in Repository.AutoParts)
                        {
                            if ((nodYear.Text == part.Year.ToString()) &
                                (nodMake.Text == part.Make))
                            {
                                if (!lstModels.Contains(part.Model!))
                                {
                                    lstModels.Add(part.Model!, part.Model!);
                                }
                            }
                        }

                        foreach (string strModel in lstModels)
                        {
                            nodMake.Nodes.Add(strModel, strModel, 6, 7);
                        }
                    }
                }

                foreach (TreeNode nodYear in nodRoot.Nodes)
                {
                    foreach (TreeNode nodMake in nodYear.Nodes)
                    {
                        foreach (TreeNode nodModel in nodMake.Nodes)
                        {
                            Collection lstCategories = new();

                            foreach (AutoPart part in Repository.AutoParts)
                            {
                                if ((nodYear.Text == part.Year.ToString()) &
                                    (nodMake.Text == part.Make) &
                                    (nodModel.Text == part.Model))
                                {
                                    if (!lstCategories.Contains(part.Category!))
                                    {
                                        lstCategories.Add(part.Category!, part.Category!);
                                    }
                                }
                            }

                            foreach (string strCategory in lstCategories)
                            {
                                nodModel.Nodes.Add(strCategory, strCategory, 8, 9);
                            }
                        }
                    }
                }
            }

            lvwSelectedParts.Items.Clear();
            lvwAvailableParts.Items.Clear();
            txtPartName.Text = string.Empty;
            txtQuantity.Text = string.Empty;
            txtSubTotal.Text = string.Empty;
            txtUnitPrice.Text = string.Empty;
            txtTaxAmount.Text = string.Empty;
            txtOrderTotal.Text = string.Empty;
            txtPartNumber.Text = string.Empty;
            txtSelectedPartsTotal.Text = string.Empty;
            pbxPartImage.Image = Image.FromFile(@"E:\College Park Auto-Parts\Generic.png");
        }

        private void Form_Load(object sender, EventArgs e)
        {
            InitializeAutoParts();
        }

        void tvwAutoParts_NodeMouseClick(object o, TreeNodeMouseClickEventArgs e)
        {
            TreeNode nodClicked = e.Node;

            if (nodClicked.Level == 4)
            {
                lvwAvailableParts.Items.Clear();
            }

            try
            {
                foreach (AutoPart part in Repository.AutoParts)
                {
                    if ((part.Category == nodClicked.Text) &&
                        (part.Model == nodClicked.Parent.Text) &&
                        (part.Make == nodClicked.Parent.Parent.Text) &&
                        (part.Year.ToString() == nodClicked.Parent.Parent.Parent.Text))
                    {
                        ListViewItem lviAutoPart = new ListViewItem(part.PartNumber.ToString());

                        lviAutoPart.SubItems.Add(part.PartName);
                        lviAutoPart.SubItems.Add(part.UnitPrice.ToString("F"));
                        lvwAvailableParts.Items.Add(lviAutoPart);
                    }
                }
            }
            catch (NullReferenceException)
            {
            }
        }

        private void miFileNewAutoPart_Click(object sender, EventArgs e)
        {
            AutoPartNew apn = new();

            apn.ShowDialog();

            InitializeAutoParts();
        }

        private void lvwAvailableParts_ItemSelectionChanged(object sender, ListViewItemSelectionChangedEventArgs e)
        {
            bool pictureFound = false;

            if (Repository.AutoParts.Count > 0)
            {
                foreach (AutoPart part in Repository.AutoParts)
                {
                    if (part.PartNumber == long.Parse(e.Item!.SubItems[0].Text))
                    {
                        pictureFound = true;
                        pbxPartImage.Image = Image.FromFile(@"E:\College Park Auto-Parts\" + part.PictureNumber! + ".png");
                        break;
                    }
                }
            }

            if (pictureFound == false)
            {
                pbxPartImage.Image = Image.FromFile(@"E:\College Park Auto-Parts\Generic.png");
            }

            Width = pbxPartImage.Right + 40;
            Height = pbxPartImage.Bottom + 75;
        }

        private void lvwAvailableParts_DoubleClick(object sender, EventArgs e)
        {
            ListViewItem lviAutoPart = lvwAvailableParts.SelectedItems[0];

            if ((lvwAvailableParts.SelectedItems.Count == 0) ||
                (lvwAvailableParts.SelectedItems.Count > 1))
                return;

            txtPartNumber.Text = lviAutoPart.Text;
            txtPartName.Text = lviAutoPart.SubItems[1].Text;
            txtUnitPrice.Text = lviAutoPart.SubItems[2].Text;

            txtQuantity.Text = "1";
            txtSubTotal.Text = lviAutoPart.SubItems[2].Text;

            txtQuantity.Focus();
        }

        internal void CalculateOrder()
        {
            double partsTotal = 0.00D;
            double taxRate = 0.00D;
            double taxAmount, orderTotal;

            if (string.IsNullOrEmpty(txtTaxRate.Text))
                txtTaxRate.Text = "7.25";

            foreach (ListViewItem lvi in lvwSelectedParts.Items)
            {
                ListViewItem.ListViewSubItem SubItem = lvi.SubItems[4];
                partsTotal += double.Parse(SubItem.Text);
            }

            try
            {
                taxRate = double.Parse(txtTaxRate.Text) / 100;
            }
            catch (FormatException)
            {
                MessageBox.Show("Invalid Tax Rate",
                                "College Park Auto-Parts",
                                MessageBoxButtons.OK, MessageBoxIcon.Information);
            }

            taxAmount = partsTotal * taxRate;
            orderTotal = partsTotal + taxAmount;

            txtSelectedPartsTotal.Text = partsTotal.ToString("F");
            txtTaxAmount.Text = taxAmount.ToString("F");
            txtOrderTotal.Text = orderTotal.ToString("F");
        }

        private void txtPartNumber_Leave(object sender, EventArgs e)
        {
            bool found = false;

            foreach (AutoPart part in Repository.AutoParts)
            {
                if (part.PartNumber == long.Parse(txtPartNumber.Text))
                {
                    txtPartName.Text = part.PartName;
                    txtUnitPrice.Text = part.UnitPrice.ToString("F");

                    if (string.IsNullOrEmpty(txtQuantity.Text))
                        txtQuantity.Text = "1";

                    txtSubTotal.Text = part.UnitPrice.ToString("F");

                    txtQuantity.Focus();

                    found = true;
                    break;
                }
            }

            if (found == false)
            {
                txtPartName.Text = "";
                txtUnitPrice.Text = "0.00";
                txtQuantity.Text = "0";
                txtSubTotal.Text = "0.00";

                MessageBox.Show("There is no part with that number.",
                            "College Park Auto-Parts",
                            MessageBoxButtons.OK, MessageBoxIcon.Information);
            }
        }

        private void txtUnitPrice_Leave(object sender, EventArgs e)
        {
            double subTotal;
            double unitPrice = 0D;
            double quantity = 0.00d;

            try
            {
                unitPrice = double.Parse(txtUnitPrice.Text);
            }
            catch (FormatException)
            {
                MessageBox.Show("Invalid Unit Price!",
                                "College Park Auto-Parts",
                                MessageBoxButtons.OK, MessageBoxIcon.Information);
            }

            try
            {
                quantity = int.Parse(txtQuantity.Text);
            }
            catch (FormatException)
            {
                MessageBox.Show("Invalid Quandtity!",
                                "College Park Auto-Parts",
                                MessageBoxButtons.OK, MessageBoxIcon.Information);
            }

            subTotal = unitPrice * quantity;
            txtSubTotal.Text = subTotal.ToString("F");
        }

        private void btnAdd_Click(object sender, EventArgs e)
        {
            if (string.IsNullOrEmpty(txtPartNumber.Text))
            {
                MessageBox.Show("There is no part to be added to the order.",
                                "College Park Auto-Parts",
                                MessageBoxButtons.OK, MessageBoxIcon.Information);
                return;
            }

            foreach (AutoPart part in Repository.AutoParts)
            {
                if (part.PartNumber == long.Parse(txtPartNumber.Text))
                {
                    ListViewItem lviSelectedPart = new ListViewItem(part.PartNumber.ToString());

                    lviSelectedPart.SubItems.Add(part.PartName);
                    lviSelectedPart.SubItems.Add(part.UnitPrice.ToString());
                    lviSelectedPart.SubItems.Add(txtQuantity.Text);
                    lviSelectedPart.SubItems.Add(txtSubTotal.Text);
                    lvwSelectedParts.Items.Add(lviSelectedPart);
                }
            }

            CalculateOrder();
        }

        private void lvwSelectedParts_DoubleClick(object sender, EventArgs e)
        {
            ListViewItem lviSelectedPart = lvwSelectedParts.SelectedItems[0];

            if ((lvwSelectedParts.SelectedItems.Count == 0) ||
                (lvwSelectedParts.SelectedItems.Count > 1))
                return;

            txtPartNumber.Text = lviSelectedPart.Text;
            txtPartName.Text = lviSelectedPart.SubItems[1].Text;
            txtUnitPrice.Text = lviSelectedPart.SubItems[2].Text;
            txtQuantity.Text = lviSelectedPart.SubItems[3].Text;
            txtSubTotal.Text = lviSelectedPart.SubItems[4].Text;

            lvwSelectedParts.Items.Remove(lviSelectedPart);
            CalculateOrder();
        }

        private void miHelpContents_Click(object sender, EventArgs e)
        {
            Help.ShowHelp(this, hpCPAP.HelpNamespace);
            // Help.ShowHelp(this, hpCPAP!.HelpNamespace, HelpNavigator.TableOfContents);
        }

        private void miHelpIndex_Click(object sender, EventArgs e)
        {
            Help.ShowHelp(this, hpCPAP!.HelpNamespace, HelpNavigator.Index, string.Empty);
        }

        /* private void miHelpSearch_Click(object sender, EventArgs e)
        {
            Help.ShowHelp(this, hpCPAP!.HelpNamespace, HelpNavigator.Find, null);
        } */

        private void miHelpAboutCollegeParkAutoParts_Click(object sender, EventArgs e)
        {
            AboutCPAP ac = new AboutCPAP();

            ac.ShowDialog();
        }

        private void miFileExit_Click(object sender, EventArgs e)
        {
            Close();
        }
    }
}

To execute the application to test it, on the main menu of Microsofot Visual Studio, click Debug and click Start Without Debugging:
On the main menu of College Park Auto-Parts, click Help and click one of the options (Contents or Index)
Close the HTML Help window and return to College Park Auto-Parts
On the main menu of the form, click File and click New Auto-Part...
On the main menu of the New Auto Part, click Help and click Presentation...
Close the HTML Help window and return to the New Auto-Part dialog box
On the title bar of the New Auto Part, click the question mark button and click the Model combo box
In the Part # text box of the New Auto Part dialog box, type 928037 and press Tab
On the main menu of the New Auto-Part, click File and click New Make...
In the Make dialog box, click the Help button
Close the HTML Help window and return to the New Auto-Part dialog box

Use the main menu of the New Auto Part dialog box to provide other information s follows:

Year:      2017
Make:      Buick
Model:     Regal
Category:  Alternators & Generators
PartName:  DB Electrical Alternator
UnitPrice: 218.74

On the main menu of the form, click File and click Save Auto Part

Create another part wiith the following information:

Part #:    290741
Year:      2015
Make:      Ford
Model:     F-150 XL 3.5L V6 Flex Regular Cab 2 Full - Size Doors
Category:  Shocks, Struts & Suspension
Part Name: Front Strut and Coil Spring Assembly - Set of 2
UnitPrice: 245.68

On the main menu of the form, click File and click Save Auto Part
On the main menu of the form, click File and click Close
On the main menu of College Park Auto-Parts, click File and click Exit
Close Microsoft Visual Studio and return to your programming environment


Previous	Copyright © 2004-2024, FunctionX	Monday 08 May 2023	Next