How to use SetupGetSourceFileLocation function get install files

var
  h: HINF;
  sClass: string;
  Context: TInfContext;
  ReturnBuffer: PChar;
  RequiredSize: DWORD;
  SourceId: UINT;
begin
  sClass := GetInfClass(AInfFile);
  h := SetupOpenInfFile(PChar(AInfFile), PChar(sClass), INF_STYLE_WIN4, nil);
  if DWORD(h) <> INVALID_HANDLE_VALUE then
  try
    SetLastError(0);
    //I don't know how to use Context parameter,GetLastError return 3758096642
    Context.Inf := h;
    Context.CurrentInf := h;
    Context.Section := 10;
    Context.Line := 10;
    SetupGetSourceFileLocation(h, @Context, nil, SourceId, nil, 0, @RequiredSize);
    if GetLastError() = ERROR_INSUFFICIENT_BUFFER then
    begin
      ReturnBuffer := GetMemory(RequiredSize);
      try
        SetupGetSourceFileLocation(h, @Context, nil, SourceId, ReturnBuffer,
          RequiredSize, nil);
      finally
        FreeMemory(ReturnBuffer);
      end;
    end
    else
      OutputDebugString(PChar(IntToStr(GetLastError())));
  finally
    SetupCloseInfFile(h);
  end;