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function UnderstandsContext(const ContextID: THelpContext;  const HelpFileName: string): Boolean;


virtual bool __fastcall UnderstandsContext(const System::Classes::THelpContext ContextID, const System::UnicodeString HelpFileName) = 0 ;


Type Visibility Source Unit Parent
function public
System.HelpIntfs IExtendedHelpViewer


Queries the Help Viewer whether it understands the given numerical ContextID.

UnderstandsContext should return True if the Help Viewer is able to display the topic identified by the numerical context identifier ContextID in the specified HelpFileName help file.

When the Help System receives a context ID-based Help request, it calls UnderstandsContext for each Help Viewer that it has registered until the method returns True. Help Viewers are polled in the order they were registered with System.HelpIntfs.RegisterViewer. The Help System then calls that Help Viewer's DisplayHelpByContext method.

In order to use UnderstandsContext, insert in the uses clause of your application the Vcl.HtmlHelpViewer or another unit that provides an interface to the external Help viewer to use. For C++, you need to include the HTMLHelpViewer.hpp header file.

See Also