HtmlHelp

C# Signature:

[DllImport("hhctrl.ocx", SetLastError=true)]
static extern IntPtr HtmlHelp( IntPtr hWndCaller, string helpFile, UInt32 command, Int32 data );

VB Signature:

<DllImport("hhctrl.ocx", EntryPoint:="HtmlHelp", CharSet:=CharSet.Auto)> _ 
Function HTMLHelp( _ 
     ByVal hWndCaller As IntPtr, ByVal pszFile As String, _ 
     ByVal uCommand As Integer, ByVal dwData As Integer) As Integer 
End Function

User-Defined Types:

Public Enum HTMLHelpCommand 
     HH_DISPLAY_TOPIC = 0 
     HH_DISPLAY_TOC = 1 
     HH_DISPLAY_INDEX = 2 
     HH_DISPLAY_SEARCH = 3 
     HH_HELP_CONTEXT = &HF 
     HH_CLOSE_ALL = &H12 
End Enum

Sample Code:

HTMLHelp(Nothing, filePath, HTMLHelpCommand.HH_HELP_CONTEXT, contextID)

Sample Code:

HTMLHelp(Nothing, filePath, HTMLHelpCommand.HH_DISPLAY_TOC, 0)