Microsoft KB Archive/224302

= How To Suppress a TextBox Control's Popup Menu =

Article ID: 224302

Article Last Modified on 7/13/2004

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APPLIES TO


 * Microsoft Visual Basic 5.0 Learning Edition
 * Microsoft Visual Basic 6.0 Learning Edition
 * Microsoft Visual Basic 5.0 Professional Edition
 * Microsoft Visual Basic 6.0 Professional Edition
 * Microsoft Visual Basic 5.0 Enterprise Edition
 * Microsoft Visual Basic 6.0 Enterprise Edition

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This article was previously published under Q224302



SUMMARY
When a user right clicks a textbox, the standard textbox popup menu appears. This article demonstrates how to suppress the textbox popup menu.



MORE INFORMATION
When a user right clicks a textbox, the textbox window receives a WM_CONTEXTMENU message. When the WM_CONTEXTMENU message is received, the textbox window shows the popup menu. A window procedure can capture all WM_CONTEXTMENU messages sent to a textbox window, thus suppressing the default popup window.

WARNING: This sample replaces the WindowProc of the text box window using a technique called a hook. Failure to unhook a window before its imminent destruction results in application errors, invalid page faults, and data loss. This is due to the fact that the new WindowProc function being pointed to no longer exists, but the window has not been notified of the change. Always unhook the sub-classed window upon unloading the sub-classed form or exiting the application. This is especially important while debugging an application that uses this technique within the Microsoft Visual Basic Development Environment. Pressing the END button on the toolbar or selecting End from the Run menu without unhooking will cause an invalid page fault and close Microsoft Visual Basic.

NOTE: This functionality is not available in any release of Microsoft Visual Basic for Applications (VBA) prior to Microsoft Office 2000.

Step-by-Step Example
 Start a new Visual Basic Standard EXE project. Form1 is created by default. Add two text boxes to Form1. Add a standard module to the project.  Add the following code to the General Declarations section of Module1: Option Explicit

Public Declare Function SetWindowLong Lib "user32" Alias _ "SetWindowLongA" (ByVal hWnd As Long, ByVal nIndex As Long, _  ByVal dwNewLong As Long) As Long Public Declare Function CallWindowProc Lib "user32" _ Alias "CallWindowProcA" (ByVal lpPrevWndFunc As Long, _  ByVal hWnd As Long, ByVal Msg As Long, ByVal wParam As Long, _   ByVal lParam As Long) As Long

Public Const GWL_WNDPROC = (-4)

Public Const WM_CONTEXTMENU = &H7B

Global lpPrevWndProc As Long Global gHW As Long

Public Sub Hook lpPrevWndProc = SetWindowLong(gHW, GWL_WNDPROC, _  AddressOf gWindowProc) End Sub

Public Sub Unhook Dim temp As Long temp = SetWindowLong(gHW, GWL_WNDPROC, lpPrevWndProc) End Sub

Public Function gWindowProc(ByVal hWnd As Long, ByVal Msg As Long, _                ByVal wParam As Long, ByVal lParam As Long) As Long If Msg = WM_CONTEXTMENU Then Debug.Print "Intercepted WM_CONTEXTMENU at " & Now gWindowProc = True Else ' Send all other messages to the default message handler gWindowProc = CallWindowProc(lpPrevWndProc, hWnd, Msg, wParam, _        lParam) End If End Function   Add the following code to the General Declarations section of Form1: Private Sub Form_Load gHW = Text1.hwnd Hook End Sub

Private Sub Form_Unload(Cancel As Integer) Unhook End Sub  Run the project. Right-click Text1. No popup menu appears. Right-click Text2 and the standard popup menu appears.</ol>

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