BUG: Mouse Captured After Clicking DBGrid Column Header (149487)


The information in this article applies to:

  • Microsoft Visual Basic Standard Edition, 32-bit, for Windows 4.0
  • Microsoft Visual Basic Professional Edition, 16-bit, for Windows 4.0
  • Microsoft Visual Basic Professional Edition, 32-bit, for Windows 4.0
  • Microsoft Visual Basic Enterprise Edition, 16-bit, for Windows 4.0
  • Microsoft Visual Basic Enterprise Edition, 32-bit, for Windows 4.0
This article was previously published under Q149487

SUMMARY

Clicking a column header in a DBGrid control of a Visual Basic program causes the mouse to remain inside the borders of the column headers. The program only responds to keyboard commands when the mouse cursor is trapped in the column header.

WORKAROUND

In order to work around the problem it is possible to add the following code to the project. Because this problem should not affect the compiled executable, it is possible to remove the workaround before debugging.

  1. Add the following code to the General Declaration section of the form: 
          #If Win32 Then
      Private Declare Function GetWindowRect Lib "user32" _
      (ByVal hWnd As Long, lpRect As RECT) As Long
      Private Declare Function ClipCursor Lib "user32" (lpRect As Any) _
      As Long
      Private Declare Function GetDesktopWindow Lib "user32" () As Long
      
      Private Type RECT
          left As Long
          top As Long
          right As Long
          bottom As Long
      End Type
      
      #Else
      Private Declare Sub GetWindowRect Lib "user" _
      (ByVal hWnd As Integer,lpRect As RECT)
      Private Declare Sub ClipCursor Lib "user" (lpRect As Any)
      Private Declare Function GetDesktopHwnd Lib "user" () As Integer
      
      Private Type RECT
          left As Integer
          top As Integer
          right As Integer
          bottom As Integer
      End Type
  2. Add the following code to the click event before the Stop: 
          Dim winrect As RECT
      #If Win32 Then
          Dim dskhwnd As Long
          Dim suc As Long
          dskhwnd = GetDesktopWindow()
          suc = GetWindowRect(dskhwnd, winrect)
          suc = ClipCursor(winrect)
      #Else
          Dim dskhwnd As Integer
          Dim suc As Integer
          dskhwnd = GetDesktopHwnd()
          Call GetWindowRect(dskhwnd, winrect)
          Call ClipCursor(winrect)
      #End If
      'Stop and/or all other code goes here
NOTE: All code should follow this patch code in the subroutine.

STATUS

Microsoft has confirmed this to be an issue in the Microsoft products listed at the beginning of this article. Microsoft is researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available.

MORE INFORMATION

To reproduce this behavior, add a DBGrid control to a form. In the click event of the DBGrid control, stop the program by adding the stop keyword. When you run the program and click the column headers of the DBGrid control, the mouse pointer cannot be moved outside the borders of the DBGrid column headers.

Steps to Reproduce Behavior

  1. Start Visual Basic or if it is already running, click New Project on the File menu.
  2. Add a DBGrid control to the Form1 form.
  3. Copy the following code sample to the Form1 code window. 
          Private Sub DBGrid1_Click()
         Stop
      End Sub
  4. On the Run menu, click start, or press the F5 key to start the program.
  5. Click the column head of the DBGrid control. The cursor remains within the boundaries of the column headers.
Modification Type:MajorLast Reviewed:6/30/2004
Keywords:kbbug KB149487
©2004 Microsoft Corporation. All rights reserved.