如何在Delphi XE2的应用程序中通过A-link（A-关键字）调用上下文帮助？

Question

如何在Delphi XE2的应用程序中通过A-link（A-关键字）调用上下文帮助？

Answer 1

All you need is this function:

procedure ShowHelpALink(const HelpFile, ALink: string);
var
  Link: THH_AKLink;
begin
  ZeroMemory(@Link, SizeOf(Link));
  Link.cbStruct := SizeOf(Link);
  Link.pszKeywords := PChar(AnsiString(ALink));
  Link.fIndexOnFail := True;
  HtmlHelp(GetDesktopWindow, HelpFile, HH_ALINK_LOOKUP, DWORD_PTR(@Link));
end;

For some reason HtmlHelp interprets the strings in the THH_AKLink record as ANSI strings. I cannot find any documentation on this. I suspect it is simply a bug in the HtmlHelp file library. I think that the strings that you pass in THH_AKLink must be ANSI strings.