Q189086: HOWTO: Create Context-Sensitive HTML Help in a Visual Basic App

Article: Q189086
Product(s): Microsoft Visual Basic for Windows
Version(s): WINDOWS:1.1,1.3,4.0,5.0
Operating System(s): 
Keyword(s): kbHTMLHelp kbVBp400 kbVBp500 kbGrpDSVB kbHTMLHelp110 kbDSupport kbHTMLHelp130
Last Modified: 11-JAN-2001

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The information in this article applies to:

- Microsoft HTML Help, versions 1.3, 1.1 
- Microsoft Visual Basic Professional Edition, 32-bit, for Windows, versions 4.0, 5.0 
- Microsoft Visual Basic Enterprise Edition, 32-bit, for Windows, versions 4.0, 5.0 
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SUMMARY
=======

This article shows you how to implement context-sensitive HTML Help in a Visual
Basic application.

Also, this article assumes that you have created an HTML Help (.chm) file to use
with context-sensitive help.

For additional information on creating HTML help files, please see the following
article in the Microsoft Knowledge Base:

  Q191118 : HOWTO: Create Context-Sensitive HTML Help in an MFC Application

The information in this article is most useful for Visual Basic 4.0 and 5.0
applications. Visual Basic 6.0 has added support for HTML Help files that
eliminates the need for calling the API directly. See Visual Basic's online help
for more information.

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

Perform the following steps in your Visual Basic application:

1. Create a new project, Form1 is created by default. Add a few controls to the
  form.

2. Add a module to the project, and add the following constants to the
  declaration section of the module:

        Public Const HH_HELP_CONTEXT = &HF

        Public Const MYHELP_FILE = "myfile.chm"

  NOTE: "myfile.chm" is the path and name of the HTML Help file (.chm) you
  created earlier.

3. Add the following HTML Help API declaration to the module:

        Public Declare Function HtmlHelpLongArg Lib "hhctrl.ocx" _
            Alias "HtmlHelpA" (ByVal hwndCaller As Long, _
            ByVal pszFile As String, ByVal uCommand As Long, _
            ByVal dwData As Long) As Long

4. Intercept the form's KeyUp method to capture the F1 key using the following
  sample code in the Form KeyUp event procedure:

        Private Sub Form_KeyUp(KeyCode As Integer, Shift As Integer)
           dim iRetCode As Long
           If KeyCode = vbKeyF1 Then
               iRetCode = HtmlHelpLongArg(Me.ActiveControl.hWnd,_
                MYHELP_FILE,HH_HELP_CONTEXT,Me.ActiveControl.HelpContextID)
           End If
        End Sub

5. Set the form's KeyPreview, WhatsThisHelp, and WhatsThisButton properties to
  TRUE.

6. Set the HelpContextID property of each control on the form to a value from
  the help project file's MAP section.

7. Run the Visual Basic application. Select a control on the form and press the
  F1 key. The appropriate context-sensitive help topic should appear on the
  screen.

REFERENCES
==========

Microsoft Visual Basic Help, version 4.0, 5.0

Additional query words:

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Keywords          : kbHTMLHelp kbVBp400 kbVBp500 kbGrpDSVB kbHTMLHelp110 kbDSupport kbHTMLHelp130 
Technology        : kbVBSearch kbHTMLHelpSearch kbAudDeveloper kbVB400Search kbVB400 kbHTMLHelp110 kbHTMLHelp130
Version           : WINDOWS:1.1,1.3,4.0,5.0
Issue type        : kbhowto

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