Q138505: HOWTO: Add Context-Sensitive Help Button to Win 95 Dialog Boxes

Article: Q138505
Product(s): Microsoft C Compiler
Version(s): 2.1,2.2,4.0,4.1,5.0,6.0
Operating System(s): 
Keyword(s): kbcode kbui kbCmnDlg kbMFC KbUIDesign kbVC210 kbVC220 kbVC400 kbVC410 kbVC500 kbVC600 k
Last Modified: 29-APR-2002

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The information in this article applies to:

- The Microsoft Foundation Classes (MFC), used with:
   - Microsoft Visual C++, 32-bit Editions, versions 2.1, 2.2, 4.0, 4.1 
   - Microsoft Visual C++, 32-bit Enterprise Edition, versions 5.0, 6.0 
   - Microsoft Visual C++, 32-bit Professional Edition, versions 5.0, 6.0 
   - Microsoft Visual C++, 32-bit Learning Edition, version 6.0 
   - Microsoft Visual C++.NET (2002) 
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SUMMARY
=======

Windows 95 provides DS_CONTEXTHELP as a dialog box style to implement
context-sensitive help in dialog boxes. The Dialog Editor included with Visual
C++ versions 2.1 and 2.2, does not provide a way to set this style when
designing the dialog box. This article shows, by example, how to add the
context-sensitive help button to the title bar of dialog boxes.

Starting with version 4.0 of Visual C++, the resource editor does allow this
extended style to be set. However, this causes the resource editor to generate a
DIALOGEX resource that is not supported on Win32s. Therefore, to stay compatible
with Win32s, you can still apply the method discussed in this article.

In Visual C++ version 5.0 and 6.0, the resource editor allows you to set both
options.

In Visual C++.NET, open the Resource View of the project and set the "Context
Help" property of the dialog box to "True".

MORE INFORMATION
================

If the DS_CONTEXTHELP style is set for a dialog box, Windows 95 adds a question
mark button to the title bar of the dialog box. When the user clicks the
question mark, the mouse pointer changes to a question mark with a pointer. If
the user then clicks a control in the dialog box, the control receives a WM_HELP
message.

To set this style, override the OnInitDialog member function of the
CDialog-derived class, and add the WS_EX_CONTEXTHELP style to the extended
styles for the dialog box. The following code illustrates this:

     BOOL CAboutDlg::OnInitDialog()
     {
          CDialog::OnInitDialog();
          LONG style = ::GetWindowLong(m_hWnd, GWL_EXSTYLE);
          style |= WS_EX_CONTEXTHELP;
          ::SetWindowLong(m_hWnd, GWL_EXSTYLE, style);
          return TRUE;
     }

NOTE: DS_CONTEXTHELP is just a placeholder. When the dialog box is created, the
system checks for DS_CONTEXTHELP and, if it is there, adds WS_EX_CONTEXTHELP to
the extended style of the dialog box.

Additional query words: kbGrpPropSheet

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Keywords          : kbcode kbui kbCmnDlg kbMFC KbUIDesign kbVC210 kbVC220 kbVC400 kbVC410 kbVC500 kbVC600 kbFAQ 
Technology        : kbAudDeveloper kbMFC
Version           : :2.1,2.2,4.0,4.1,5.0,6.0
Issue type        : kbhowto

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