How To Create Context-Sensitive HTML Help in a Visual Basic App

MORE INFORMATION

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.