PRB: Toolbar Buttons Not Updated/Painted Correctly in Windows 95

ID: Q168289

The information in this article applies to:

The Microsoft Foundation Classes (MFC), included with:
- Microsoft Visual C++, 32-bit Editions, versions 4.0, 4.1, 4.2, 4.2b, 5.0

SYMPTOMS

Buttons on a toolbar that were created using CToolBar may not update or paint correctly if the buttons have text associated with them. This happens only on Windows 95 machines with Internet Explorer 3.x installed.

CAUSE

This is due to a bug in the ComCtl32.dll (version 4.70) that is installed with Internet Explorer 3.x.

RESOLUTION

To work around this problem, derive a class from CToolBar and override DefWindowProc as follows:


   // MyToolBar.h : headerfile
   class CMyToolBar : public CToolBar
   {
   ...
   protected:
      virtual LRESULT DefWindowProc(UINT message, WPARAM wParam,
         LPARAM lParam);
   ...
   };


   // MyToolBar.cpp : implementation file
   #include "stdafx.h"
   #include "mytoolbar.h"
   ...
   LRESULT CMyToolBar::DefWindowProc(UINT message, WPARAM wParam,
      LPARAM lParam)
   {
      // the toolbar common control does not handle these messages well
      // if the WS_VISIBLE style is not turned on under Windows 95
      DWORD style = GetStyle();
      if (message == TB_DELETEBUTTON || message == TB_INSERTBUTTON)
      {
         if (!(style & WS_VISIBLE))
         {
            ModifyStyle(0,WS_VISIBLE);
         }
      }
      LRESULT lresult = CToolBar::DefWindowProc(message, wParam, lParam);
      if (message == TB_DELETEBUTTON || message ==TB_INSERTBUTTON)
      {
         if (!(style & WS_VISIBLE))
         {
            ModifyStyle(WS_VISIBLE,0);
         }
      }
      return lresult;
   }

You can derive the CToolBar by using ClassWizard to derive from "generic CWnd" and changing all CWnd references to CToolBar.

STATUS

Because Microsoft Visual C++, version 6.0 requires Internet Explorer 4.01, Service Pack 1, this problem no longer exists in Visual C++, version 6.0.

MORE INFORMATION

Steps to Reproduce Behavior

Add the following code to CMainFrame::OnCreate in a Default Appwizard Application:


   BOOL CMainFrame::OnCreate(...)
   {
      ...
      m_wndToolBar.SetButtonText(0,"New");
      m_wndToolBar.SetButtonText(1,"Open");
      m_wndToolBar.SetButtonText(2,"Save");
      m_wndToolBar.SetButtonText(4,"Cut");
      m_wndToolBar.SetButtonText(5,"Copy");
      m_wndToolBar.SetButtonText(6,"Paste");
      m_wndToolBar.SetButtonText(8,"Print");
      m_wndToolBar.SetButtonText(9,"About");

      CRect temp;
      m_wndToolBar.GetItemRect(0,&temp);
      m_wndToolBar.SetSizes( CSize(temp.Width(),temp.Height()),
         CSize(16,15));

      return 0;

   }

Additional query words:

Keywords : kbcode kbui kbMFC KbUIDesign kbVC kbVC400 kbVC410 kbVC420 kbVC500
Version : 4.0 4.1 4.2 4.2b 5.0
Platform : NT WINDOWS
Issue type : kbprb