E2003 Undefinierter Bezeichner: 'QueryInterface'

[DeddyH]

Vielleicht wird es so etwas klarer:

Delphi-Quellcode:

program TestInterface;

{$APPTYPE CONSOLE}


uses
  SysUtils;

type
  ITest = interface
    ['{A6C342E9-61FE-404C-BAB2-7618E6387E5F}']
    procedure DoTest;
  end;

  IDings = interface
    ['{A5F98113-D65A-4268-98E4-B43FC4D5FA3B}']
    procedure DoDings;
  end;

  TTest = class(TInterfacedObject, ITest, IDings)
    procedure DoTest;
    procedure DoDings;
  end;

  { TTest }

procedure TTest.DoTest;
begin
  writeln('Methode DoTest von ITest');
end;

procedure TTest.DoDings;
begin
  writeln('Methode DoDings von IDings');
end;

var
  t: ITest;
  d: IDings;

begin
  t := TTest.Create;
  t.DoTest;
  if Supports(t, IDings, d) then
    d.DoDings;
  readln;
end.