Building a Program

Executing a Program

Although you can creat a complete and fully functional application using a text editor, Microsoft Visual Studio and Microsoft Visual Basic 2010 Express provide a graphical environment that is more convenient. You start by creating a project. To create a project:

• On the main menu, click File -> New Project...
• On the Start Page, click New Project...
• Press Ctrl + N

When you start a new application from the New Project dialog box, you are asked whether you want to create a new solution too, and you must give it a name. By default, the new project and solution would hold the same name. If you accept the suggestions, you would get a main folder with the name of the project. Inside of that folder, there would be a folder with the same name. That inside folder would represent the project.

After creating a solution, its name appears on the title bar of Microsoft Visual Studio. The name of the project would appear in the Solution Explorer.

1. Launch either Microsoft Visual Studio or Microsoft Visual Basic 2010 Express
2. On the main menu, click File -> New Project...
3. If you are using Microsoft Visual Studio, in the left list, expand Visual Basic and click Windows. In the right list, click Empty Project. Change the Name to GeneralCensus before clicking OK
    
   
   If you are using Microsoft Visual Basic 2010 Express, in the middle list, click Console Application. Change the Name to GeneralCensus
   Click OK

The Solution Explorer is a window that displays a list of the files that make up a project. To access the Solution Explorer:

• If the Solution Explorer is not yet showing on the screen:
  • On the main menu, click View -> Solution Explorer
  • On the Standard toolbar, click the Solution Explorer button
• If the Solution Explorer is already showing, click its tab

The Solution Explorer is made of four sections. Like every regular window, the Solution Explorer is equipped with a title bar that displays its name on the left side and three buttons on the right side:

• The Window Position button displays a menu when you click it:
   
  
   
  The Float option is enabled if the window is docked to a side of the screen. The Float option is disabled if the window is already floating. If the window is docked and you click Float, it would be moved from its docked position and would float. As an alternative to float a docked window, drag its title bar away from its docked position:
   
  
  
  To dock a floating  window, drag its title bar

Under its title bar, the second section of the Solution Explorer is a toolbar::

• The Properties button allows you to display the Properties window
• The Show All Files button is used to show the hidden files of the project
•  As its name indicates, the Refresh button is used to refresh the list of files and resources of the project
• The View Code button is used to show the code of a class

The third part of the Solution Explorer is its body. It shows the folders, files, and resources that are part of the current project. To expand a node, you can either click its button or double-click its name. To collapse a node, either click its button or double-click it.

The root of the list is the name of the solution. Under the root is the name of the current project. If the solution contains more than one project, the name of each project is represented under the solution. Inside of the project are its folders, files, and resources. The first item under a project name is References. After the References node, there are the names of the classes that are part of the project.

The fourth part of the Solution Explorer is its tab.

The Properties window shows the Windows operating system's details of the files or resources used in a project. To display it:

• If the Properties window is not yet displaying
  • Oon the main menu, click View -> Properties window
  • On the Standard toolbar, click the Properties button
• If the Properties window is displaying already, click its tab

The display and rectangular behavior of the Properties window follows the description we had for the Solution Explorer.

To show the operating system's characteristics of a project or a file, in the Solution Explorer, click the object:

• If you click a solution, the Properties window would show its name and its location
• If you click a project, the Properties window would show its project file
• If you click a file, the Properties window would show its name (in the File Name field) and its location (in the Full Path) field

The Properties window displays different fields depending on the item selected in the Solution Explorer. You can change some things in the Properties window. When a field is disabled, it means you cannot modify it.

A solution is used to coordinate the different aspects of an application that is being created. When you have created a project, the name of the solution displays as the top node of the tree in the Solution Explorer:

The title bar of the studio displays the name of the solution in the left section:

If you start saving a project for the first time, it would bring the Save Project dialog box. By default, Microsoft Visual Studio selects your personal directory as the path to the solution. This is called the location. In the location, Microsoft Visual Studio creates a folder as the solution of the project. The solution must have, or must be stored, in its own folder. As mentioned earlier, Microsoft Visual Studio uses the name of the project as the name of the solution. To rename the solution, you can change the string in the Solution Name text box. Remember that you can enter the name of the project in the Name text box. Here is an example:

When you save a project (for the first time), by default, Microsoft Visual Studio creates a new folder for it in the Documents\Visual Studio 2010\Projects folder. It uses the name of the solution to name the folder. It creates some files and stores them in that new folder. Then, it creates a sub-folder, using the name of the project, inside of the folder of the solution. Besides the sub-folder with the name as the project, it creates another folder named debug. It also creates another folder named Debug in the sub-folder of the name of the project. In each folder and some other folders, it creates some files that we will not pay attention to for now.

If the project had already been saved but you want to change the name of the solution, on the main menu, you can click File -> Save solution-name.sln As... This would bring the Save File As dialog box where you can specify the name of the solution and click Save.

If you don't like the name of a solution, to rename it, in the Solution Explorer, right-click it and click Rename:

As an alternative, in the Solution Explorer, click the name of the project, in the Properties window, click the value of the (Name) field, then edit it or type a new one:

Deleting a Solution is equivalent to deleting a file. To delete a solution, use a file utility such as Windows Explorer, locate the folder that contains the solution, and delete it.

If you are creating your application using a text editor, you must save your file(s) in a folder you will create. When Microsoft Visual Studio 2010 (any edition) is installed, it creates a folder named Visual Studio 2010 in your Documents folder. The Documents folder is called your personal drive or your personal directory. Inside of the Visual Studio 2010 folder, it creates a sub-folder named Projects. By default, this is where it would save your projects, each with its own folder.

To save a project, on the Standard toolbar, you can click the Save All button . Alternatively, on the main menu, you can click File -> Save All. If the project had already been saved but you want to save it under a different name, on the main menu, you can click File -> Save project name As...

There are a various ways you can open an existing project:

• On the main menu, click File -> Open Project...
• On the Start Page, click Open Project...
• Press Ctrl + Shift + O

A solution in Microsoft Visual Studio can contain one or more projects. That is, after creating the first project, you can add another project to the same solution and you can add as many projects as you want.

To add a new project to a solution (in Microsoft Visual Studio):

• On the main menu, click File -> Add -> New Project...
• In the Solution Explorer, right-click the name of the solution, position the mouse on Add, and click New Project...

This would display the Add New Project dialog box. In the Templates list, select the type of project you want. Accept or change the name of the project, then click OK.

The names of the different projects are listed in the Solution Explorer.

To rename a project, in the Solution Explorer, right-click its name under the solution and click Rename. Type the new name and press Enter.

As mentioned already, a project can contain many files. If you are using a text editor, you can create and save files continuously as you see fit. If you are using Microsoft Visual C# 2010 Express or Microsoft Visual Studio, to add a new file to a project:

• On the main menu, click Project -> Add New Item...
• In the Solution Explorer, right-click the name of the project, position the mouse on Add, and click New Item...

This would display the Add New Item dialog box. From there, select the type of file you want. Accept or change its name. Then click Add.

When a project is made of various files, each file is represented by a label in the top section of the Code Editor. Here are examples:

Each file is also represented in the main menu under Windows.

When working on a project, if there is a file in another project and you want to use that file in your project, you can import that file. To do this;

• On the main menu, click Project -> Add Existing Item...
• In the Solution Explorer, right-click the name of the project to which you want to import the file, position the mouse on Add, and click Existing Item...

Any of these actions would display the Add Existing Item dialog box with the name of the project on the title bar. Locate the file, select it, and click Open.

If you are using a text editor to write your code, you can use that editor to open a file. For example, in Notepad, you can click File -> Open... If you are trying to open a source file, first change the file type combo box to All Files (*). Then locate the file from its folder and click Open.

In Microsoft Visual Studio or Microsoft Visual C# Express, if a file is a member of the current project, to open it:

• On the main menu, click Window and click the name of the file
• On the main menu, click File -> Open File...
• In the top section of the Code Editor, click the label that holds the name of the file

To open a file:

• In the Solution Explorer, double-click the name of the file
• On the Standard toolbar, click the Open File button

This would display the Open File dialog box. From there, locate the file from its folder and click it.

You can change the name of a file after starting a project. To do this, in the Solution Explorer, under the project that holds the file, right-click the file and click Rename. Type the desired name and press Enter.

If you have a file in a project but do not need that file anymore, you can delete it. To remove a file, in the Solution Explorer, under the project, right-click the name of the file and click Delete.

1. If you are using Microsoft Visual Basic 2010 Express, in the Solution Explorer, right-click Module1.vb and click Delete. When asked whether you want to permanently delete, click OK.
   In either studio, to add a new file, on the main menu, click Project -> Add New Item...
2. In the middle list, click Code File
3. Set the Name to Management
    
   
    
   
4. Click Add

After creating or opening a file, you can add the necessary code to it. Microsoft Visual Basic ships with many skeleton codes you can use and customize. It writes the primary code for you and add all the necessary default behaviors. Once it has done this, you can change or remove any section. To access these code skeletons, in the section of the file where you want to add it, right-click and click Insert Snippet...:

In the menu that comes up, double-click a category:

Then double-click another category. This would display a list of code types:

If you see the type of code you want to use, double-click it.

In some cases, if you have already written some code, you may want to change it or rather add some code to it. The Code Editor provides some skeleton codes you can use. To use this approach, right-click the code you want to modify and click Surround With... In the list that appears, double-click the desired option.

• In the empty document, type the following:

  Module Statistics
  
      Sub Main()
          MsgBox("We are performing a general census of our population")
      End Sub
  
  End Module

If you add many files to a project, you must specify what file should be processed first. If you create a console application using Microsoft Visual Studio or Microsoft Visual Basic 2010 Express, the first file you create is set as the default.

To specify the starting file of your project, on the main menu, click Project -> ProjectName Properties... In the Startup Object combo box, select the file.

1. On the main menu, click Project -> GeneralCensus Properties
2. Click the arrow of the Startup Object combo box and select Statistics
3. To test the application, on the main menu, click Debug -> Start Debugging
4. Read the text of the message box
5. Click OK on the message box

Code is written in a wide area with a white background. This is the area you use the keyboard to insert code with common readable characters. The Code Editor uses some colors to differentiate categories of words or lines of text.

The colors used are highly customizable. To change the colors, on the main menu, you can click Tools -> Options... In the Options dialog box, in the Environment section, click Fonts and Colors. To set the color of a category, in the Display Items section, click the category. In the Item Foreground combo box, select the desired color. If you want the words of the category to have a colored background, click the arrow of the Item Background combo box and select one:

In both cases, the combo boxes display a fixed list of colors. If you want more colors, you can click a Custom button to display the Color dialog box that allows you to "create" a color.

Indentation is another feature that makes your program easy to read. Indentation is a technique of grouping lines of code by category. To delimit the items of your code, you should indent them by two empty spaces or one tab. Indentation should be incremental. That is, when a line of code appears to be a child of the previous line, the new line should be indented.

To control the indentation of your code, on the main menu, click Tools -> Options... In the left list, Text Editor amd expand Basic. You can then use the options in VB Specify and Editor:

After making the changes, click OK to validate or Cancel to ignore.

A comment is text that the compiler does not process when reading your code. As such, a comment can be written any way you want. In the Visual Basic language, the line that contains a comment can start with a single quote. Here is an example:

Module Module1

    Sub Main()
        ' This line will not be considered as part of the code
    End Sub

End Module

Alternatively, you can start a comment with the Rem keyword. Anything on the right side of rem, Rem, or REM would not be processed. Here is an example:

Module Module1

    Sub Main()
        ' This line will not be considered as part of the code
	Rem I can write anything I want on this line
    End Sub

End Module

Comments are very useful and you are strongly suggested to use comments regularly. They can never hurt your code and they do not increase the size of your application. Comments can help you and other people who read your code to figure out what a particular section of code is used for, which can be helpful when you re-visit your code after months or years of not seeing it.

When writing code, you will have to separate different parts with spaces, like the one between Sub and Main. This is referred to as white space. The amount of space you put between two words is not important. The compiler would ignore the white spaces between words. This means that Sub Main() and Sub            Main() would the same effect. In the same way

Sub Main()

and

Sub                                      Main()

would produce the same effect.