.NET Classes and Objects: Cursors

	.NET Classes and Objects: Cursors

Introduction

A cursor is a small picture that represents the position of the mouse on a Windows screen. Because Microsoft Windows is a graphic-oriented operating system, when it installs, it creates a set of standard or regularly used icons. These can be seen by opening the Control Panel window and double-clicking the Mouse icon. This opens the Mouse Properties dialog box where you can click the Pointers tab to see a list of standard cursors installed by Windows:

Microsoft Visual Studio .NET provides a rich collections of cursors you can easily use in your application. You can apply them to any control as you wish. To do this, access the properties of the control and open the Cursor field. If those cursors are not enough, which is not unusual, you have various options. You can use one of the many cursors installed by Visual Studio .NETin Drive:\Program Files\Microsoft Visual Studio\Common\Graphics\Cursors.

Practical Learning: Introducing Cursors

Start a new Windows Forms Application named Resources2
Change the Text property of the form to GDI+ Resources
On the Toolbox, click the ListBox control and click the upper-left section of the form
Again, on the Toolbox, click the Panel control and click the upper-right section of the form
Once again, on the Toolbox, click the TreeView control and click the lower-left section of the form
On the Toolbox, click the RichTextBox control and click the upper-right section of the form

Creating Cursors

To create and design your own cursor, you can use Visual Studio .NET. To do this, on the main menu of Visual Studio, you can click Project -> Add New Item… Then, in the Add New Item dialog box, you can select Cursor File, give it a name and click Open.

A cursor is a Windows file that has the extension .cur

Practical Learning: Creating a Cursor

To create a new cursor, on the main menu of Visual Studio .NET, click File -> New -> File...
In the New File dialog box and in the Templates section, double- click Cursor File
Use the Eraser tool to wipe the area of the new cursor image
On the Image Editor toolbar, click the Line tool . In the Colors window, make sure the black color is selected
Draw a vertical line from the pixel on the 6th column and 2nd row from top
Draw a diagonal line at 45˚ from the top border of the new line to the lower-right until the line is at 5 pixels from the right border of the drawing area
Draw a horizontal line from the lower border of the dialog line to half-left
Draw a diagonal line from the lower border of the vertical line to the left border of the horizontal line:
Draw another diagonal line from the top corner of the current shape to the intersection of horizontal and left diagonal line:
On the Image Editor toolbar, click Fill
In the Colors window, click the button with a pink monitor
In the drawing area, click the right triangle.
In the Colors window, click the white color
On the drawing area, click in the left triangle
To set the position of the cursor pointer, on the Image Editor toolbar, click the Set Hot Spot Tool
Click the tip of the cursor at the intersection of vertical and the the diagonal lines in the top-left section
To save the cursor, on the Standard toolbar, click the Save All button
Locate the Resources2\Bin folder and display it in the Save In combo box
Change the File Name to Push and press Enter

Using Cursors

There are two main ways you can use a cursor in your application. The easiest cursors are listed in the Cursor field of the Properties window for the control whose cursor you want to change. The available cursors are:

You can select one of these cursors in the Properties window and assign it to a control. These cursors are defined in a class called Cursors. This simple class mostly contains only a list of available cursors as properties. All these cursors are represented as static properties. Therefore, to use one of these cursors, call the name of the class, Cursors, followed by the period operator, followed by the name of the cursor as it appears in the above list.

Another technique consists of using a cursor not listed in the Properties window. A cursor is based on the Cursor class. It provides four constructors. One of them allows you to specify the path where the cursor is located. This constructor has the following syntax:

Public Sub New(ByVal fileName As String)

The argument passed to this constructor is name or the location of the cursor as a file. After calling this constructor to initialize a Cursor variable, the cursor is ready. You can then use it as you see fit. For example, you can assign it to the Cursor property of a control.

When the cursor of a control has been changed, the control fires a CursorChanged event. This event is of type EventArgs.

If at any time you want to hide a cursor, you can call the Cursor::Hide() method. Its syntax is:

Public Shared Sub Hide()

To display the cursor again, you can call the Cursor::Show() method. Its syntax is:

Public Shared Sub Show()

Practical Learning: Using Cursors

Display the form. Click the control on the upper-left section of the form
In the Properties window, click the arrow of the combo box of the Cursor field and select PanNorth
Double-click an unoccupied area of the form to access its Load event

To programmatically assign cursors, implement the event as follows:

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Dim curPush As System.Windows.Forms.Cursor = New System.Windows.Forms.Cursor("Push.cur")
        Dim curPalette As System.Windows.Forms.Cursor = _
            New System.Windows.Forms.Cursor( _
            "C:\Program Files\Microsoft Visual Studio .NET 2003\Common7\Graphics\cursors\PALETTE.CUR")

        Me.Panel1.Cursor = Cursors.NoMove2D
        Me.TreeView1.Cursor = curPush
        Me.RichTextBox1.Cursor = curPalette
    End Sub

Execute the application to test it
Close the form and return to your programming environment


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