Übergabeparameter in Funktion

[DeddyH]

Dann definier Dir doch eine Basisklasse, die die Methode (abstrakt) deklariert und leite die weiteren davon ab.

Delphi-Quellcode:

unit Unit6;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;

type
  TMyBaseClass = class
  protected
    function TuWas(const Value: Integer): Integer;virtual;abstract;
  end;

  TClassA = class(TMyBaseClass)
  public
    function TuWas(const value: Integer): Integer;override;
  end;

  TClassB = class(TMyBaseClass)
  public
    function TuWas(const value: Integer): Integer;override;
  end;

  TForm6 = class(TForm)
    btn1: TButton;
    procedure btn1Click(Sender: TObject);
  private
    { Private-Deklarationen }
    procedure Test(const obj: TMyBaseClass);
  public
    { Public-Deklarationen }
  end;

var
  Form6: TForm6;

implementation

{$R *.dfm}

{ TClassB }

function TClassB.TuWas(const value: Integer): Integer;
begin
  Result := value * 2;
end;

{ TClassA }

function TClassA.TuWas(const value: Integer): Integer;
begin
  Result := value * 3;
end;

{ TForm6 }

procedure TForm6.btn1Click(Sender: TObject);
var c1, c2: TMyBaseClass;
begin
  c1 := TClassA.Create;
  try
    c2 := TClassB.Create;
    try
      Test(c1);
      Test(c2);
    finally
      c2.Free;
    end;
  finally
    c1.Free;
  end;
end;

procedure TForm6.Test(const obj: TMyBaseClass);
begin
  if Assigned(obj) then
    ShowMessage(IntToStr(obj.TuWas(2)));
end;

end.