C# Signature:
[DllImport("user32.dll")]
static extern int SetWindowLong(IntPtr hWnd, int nIndex, int dwNewLong);
VB.NET Signature:
Private Declare Auto Function SetWindowLong Lib "User32.Dll" _
(ByVal hWnd As IntPtr, _
ByVal nIndex As Integer, _
ByVal dwNewLong As Integer) As Integer
User-Defined Types:
None.
Notes:
None.
Tips & Tricks:
Certain window data is cached, so changes you make using SetWindowLong will not take effect until you call the SetWindowPos function. Specifically, if you change any of the frame styles, you must call SetWindowPos with the SWP_FRAMECHANGED flag for the cache to be updated properly.
Sample Code:
The following sample uses the GetWindowLong and SetWindowLong to remove the 3D border in the MDI client area.
Private Declare Auto Function SetWindowLong Lib "User32.Dll" (ByVal hWnd As IntPtr, ByVal nIndex As Integer, ByVal dwNewLong As Integer) As Integer
Private Declare Auto Function GetWindowLong Lib "User32.Dll" (ByVal hWnd As System.IntPtr, ByVal nIndex As Integer) As Integer
Private Const GWL_EXSTYLE = (-20)
Private Const WS_EX_CLIENTEDGE = &H200
Private Sub RemoveMdiBorder()
For Each c As Control In Me.Controls
If TypeOf c Is MdiClient Then
Dim windowLong As Long = GetWindowLong(c.Handle, GWL_EXSTYLE)
windowLong = windowLong And (Not WS_EX_CLIENTEDGE)
SetWindowLong(c.Handle, GWL_EXSTYLE, windowLong)
c.Width = c.Width + 1
Exit For
End If
Next
End Sub
Alternative Managed API:
Do you know one? Please contribute it!
