How to Retrieve Mouse Cursor Coordinates in Visual Basic

• Standard and Professional Editions of Microsoft Visual Basic for Windows, versions 2.0 and 3.0

SUMMARY

Applications such as Paint programs use functions from the Windows API (Application Programming Interface) to retrieve Mouse coordinates that in turn help the user design and paint their picture. This article shows by example how to use the Windows API GetCursorPos() function to retrieve the mouse coordinates from Visual Basic.

MORE INFORMATION

The GetCursorPos() function returns a structure that contains the current position of the caret. To call the GetCursorPos() function from Visual Basic, you have to set up a Type structure. This is shown in the following example.

Step-by-Step Example

1. Start a new project in Visual Basic. Form1 is created by default.

2. From the File Menu, choose New Module.

3. Add the following code in the General Declarations section of the new module:

   Type POINTAPI ' This holds the logical cursor information

         x As Integer
         y As Integer
   

   End Type

      Declare Sub GetCursorPos Lib "User" (lpPoint As POINTAPI)
   
   

4. Add a timer control (Timer1) to the form.

5. Add the following code to the Form_load event:

      Sub Form_Load ()
         timer1.Interval = 100
      End Sub
   
   

6. Add the following code to the Timer1_Timer event:

      Sub Timer1_Timer ()
         Dim rect As POINTAPI
         ' Get the current mouse cursor coordinates:
         Call GetCursorPos(rect)
         FORM1.Cls
         ' Print out current position on the form:
         Print "Current X = " & rect.x
         Print "Current Y = " & rect.y
      End Sub
   
   

7. Run the Program. You should be able to see the cursor coordinates change whenever you move the mouse around the screen.

REFERENCES

"Programming Windows: the Microsoft Guide to Writing Applications for Windows 3," Charles Petzold, Microsoft Press, 1990

"Microsoft Windows Software Development Kit" Reference Manuals and on-line help

WINSDK.HLP file shipped with Microsoft Windows 3.0 Software Development Kit

"Visual Basic Programmers Guide to the Windows API", Daniel Appleman, Ziff Davis Press, 1993