How to remove MDI Client Border

[circuits2]

I will add more of an explanation later.

This is how you can remove the border and set the backcolor of the MDIClient control, which is the control that is automatically added to your form when you set its IsMdiContainer property to True.


Add the following inside your class:

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

Then add the following to the MDI Parent's load event:

' SET BACKGROUND COLOR AND REMOVE BORDER FROM MDICLIENT CONTROL
For Each c As Control In Me.Controls()
    If TypeOf (c) Is MdiClient Then
        c.BackColor = Color.DimGray
        Dim windowLong As Integer = 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
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