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

• Microsoft HTML Help, versions 1.3, 1.1
• Microsoft Visual Basic Standard, Professional, and Enterprise Editions, 32-bit only, for Windows, versions 4.0, 5.0

SUMMARY

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

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

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:

Keywords : kbHTMLHelp kbVBp400 kbVBp500 kbGrpVB kbHTMLHelp110 kbDSupport kbHTMLHelp130
Version : WINDOWS:1.1,4.0,5.0
Platform : WINDOWS
Issue type : kbhowto