Microsoft & .NETVisual BasicVB Coding Tip: Only Allow Numbers in a Nodes Text

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This treeview tip again uses the SendMessage API call to find the edit window in the treeview and then send a message to it, the ES_NUMBER message to only allow numbers.

Private Declare Function SendMessage _
     Lib "user32" Alias _
  "SendMessageA" (ByVal hwnd As Long, _
                  ByVal wMsg As Long, ByVal _
                  wParam As Long, _
                  lParam As Any) As Long

Private Const TV_FIRST = &H1100
                              TV_FIRST + 15
Private Const ES_NUMBER = &H2000

Private Sub NumbersOnly(tvw As Treeview)
    Dim lngHwnd As Long  

    lngHwnd = SendMessage(tvw.hwnd, _
                          TVM_GETEDITCONTROL, _
                          0, 0)

    If lngHwnd <> 0 Then
        SendMessage lngHwnd, ES_NUMBER, 0, 0
    End If
End Sub

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