Keskustelu: Ohjelmointikysymykset: VB.NET: Oma osoitin

SYMPTOMS
When you use a color cursor for a form's MousePointer, it appears in black and white rather than in color.



CAUSE
Visual Basic does not provide any support for color cursors and, therefore, a color cursor cannot be used while running in the Visual Basic IDE. However, a color cursor can be used in compiled Visual Basic applications. Please see the "More Information" section for details.



RESOLUTION
There are two ways to get color cursors in the compiled application:

You can use Icons instead of actual cursors. These display in color, but the Hot Spot is always at the center of the image and you cannot change it.


The best solution is to use the LoadResPicture function to load the color cursor(s) from a Resource file. This way the Operating System provides the support and the colors do appear when running the compiled application.



STATUS
This behavior is by design.



MORE INFORMATION
The Resource file can be created with the Visual Basic 6.0 Resource Editor Add-In, and the cursor files can be created with the ImagEdit.exe tool included with Visual Basic 6.0. The ImagEdit.exe tool is located on Disk1 of Visual Basic or Disk3 of Microsoft Visual Studio in the following folder:

\Common\Tools\Vb\Imagedit
This tool also allows you to set the Hot Spot for the cursor, which determines the exact point of the image for purposes of clicking, MouseOver event, and so forth. When you have the cursor file open, you should have an icon that looks like an arrow with lines emanating from the tip in the lower-right of the Toolbox. When you click on this icon to select it and then click on the image where you want the hot spot to be, you see the coordinates listed in the Toolbar where it says "Hotspot."
Step-by-Step Example of Loading Color Cursors from a Resource File
Start a Standard EXE project in Visual Basic. Form1 is created by default.


On the Add-Ins menu, click to select Add-In Manager . From the list of Add-Ins, click to select VB 6 Resource Editor , check Loaded/Unloaded in the lower-right of the dialog box, and then click OK .


On the Project menu, click to select Add New Resource File . In the Open dialog box, type ColorCursors.res for FileName, and then click OK . Click OK again on the dialog box that asks to create this file.


On the Properties window, expand Related Documents, and double-click on ColorCursors.res to open the file in the Resource Editor.


On the Toolbar, click on the button that looks like an arrow pointer over an hourglass (the Tooltip displays Add cursor ...)


In the Open dialog box, navigate to the Cursors folder and select a color cursor. By default, Visual Basic creates this folder at this location:
C:\Program Files\Microsoft Visual Studio\Common\Graphics\Cursors\
If you are unable to locate this folder it is probably because these graphics were not installed. Either use four other cursors, create four cursors using the ImagEdit.exe tool, or follow instructions in "Steps to Install the Visual Studio Graphics Files" later.


Add three more color cursors in this same way. Note that these are numbered 101 - 104 in the editor. This is the Resource ID. Close the Editor window.


Add a CommandButton control to Form1.


Place the following code into the code window of Form1:


Option Explicit

Dim ResID As Integer

Private Sub Command1_Click()
If ResID = 104 Then ' last cursor
ResID = 101 ' start over
Else
ResID = ResID + 1
End If
Me.MouseIcon = LoadResPicture(ResID, vbResCursor)
End Sub

Private Sub Form_Load()
Me.MousePointer = vbCustom
ResID = 100 ' Starting value. We add 1 right away before it is used.
End Sub
Save and compile the project.


Press the F5 key to run the project. Each time you click on Command1, the cursor changes, but it is always monochrome (black and white.)


Start the Windows Explorer and run the .exe file. Again, each time you click on Command1, the cursor changes, but the cursors now display in their proper colors.


Steps to install the Visual Studio Graphics files
Make sure that Visual Basic is not running. On the Start menu, locate Settings , select Control Panel , and then double-click on Add/Remove Programs .


Select your product from the list. It will either be Microsoft Visual Studio 6.0 or Microsoft Visual Basic 6.0 (Professional or Enterprise). Click on the Add/Remove Programs button.


From the Setup Maintenance window, click on the Add/Remove Programs button.


Select Graphics from the list of Options, and press either Continue or Change Option to select only the types of graphics you want to install. Click OK . Click Continue and follow the instructions on the screen.

The ...\Cursors folder should now be available.



REFERENCES
For additional information, click the article numbers below to view the articles in the Microsoft Knowledge Base:

Q138529 PRB: Visual Basic 4.0 Does Not Support Color Cursor Files
Q194409 RESFILE.EXE Stores Any File Type in a Resource File
MSDN Help topic: "Anatomy of a Resource