Opening help files by topic name or by Help ID

The Dr.Explain is a useful help authoring tool for creating context sensitive help files.

The MS HTMLhelp API allows opening a specific topic within the CHM file from your software. Thus, with the CHM file you can easily implement a context sensitive help functionality in your software application.

This sample code for Visual Basic demonstrates how to open a certain page of the help file:

Private Declare Function HtmlHelp Lib "HHCtrl.ocx" Alias "HtmlHelpA" _

        ( ByVal hWndCaller As Long, _

          ByVal pszFile As String, _

          ByVal uCommand As Long, _

          dwData As Any) As Long

Const HH_DISPLAY_TOPIC As Long = 0

Private Sub CommandF1_Click()

      HtmlHelp hWnd, sPathToCHM, HH_DISPLAY_TOPIC, ByVal "topic_name.htm"

End Sub

... or by Help ID:

Private Sub CommandF1_Click()

        HtmlHelp hWnd, sPathToCHM, HH_HELP_CONTEXT, ByVal 2000&

End Sub

This approach can be easily applied for other programming languages, e.g. for C\C++ application this may look like this:

void OnHelp()

{

    HtmlHelp(hWnd, sPathToCHM, HH_DISPLAY_TOPIC, (DWORD)_T("topic_name.htm"));

};

... or by Help ID:

void OnHelp()

{

    HtmlHelp(hWnd, sPathToCHM, HH_HELP_CONTEXT, (DWORD)2000);

};

The Dr.Explain is a handy help authoring tool for creating context sensitive help files in CHM format.