unit1.pas

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unit Unit1;

interface

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

type
  TControlClass =class of TControl;
  TForm1 = class(TForm)
    RadioGroup1: TRadioGroup;
    Button1: TButton;
    Label1: TLabel;
    procedure Button1Click(Sender: TObject);
  private
    procedure createControlObj(ControlClass:TControlClass);
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}
procedure TForm1.createControlObj(ControlClass:TControlClass);
  var AControlObj:TControl;
begin
  AControlObj:=ControlClass.Create(self);
  AControlObj.Parent:=self;
  AControlObj.Name:=AControlObj.ClassName;
  AControlObj.SetBounds(10,10,250,150);
  label1.Caption:=AControlObj.ClassName;
end;

procedure TForm1.Button1Click(Sender: TObject);
const
 ContrlClassArry:array[0..2] of TControlClass=(TMonthCalendar,TMemo,TColorBox);
var
  i:integer;
begin
  for  i:=0  to controlcount-1 do
  if (Controls[i] is TMonthCalendar) or (Controls[i] is TMemo)
     or (Controls[i] is TColorBox) then
  Controls[i].Free;
  createControlObj(ContrlClassArry[RadioGroup1.ItemIndex]);
end;

end.