Delphi动态创建组件

unit Unit1;

interface

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

type
  TForm2 = class(TForm)
    procedure FormClose(Sender: TObject; var Action: TCloseAction);
  private

  public  

  //拦截Left mouse down 消息

       procedure WMMOUSEDOWN(var Msg:TWMLButtonDown);message WM_LBUTTONDOWN;
  end;

var
  Form2: TForm2;

implementation

{$R *.dfm}

procedure TForm2.FormClose(Sender: TObject; var Action: TCloseAction);
var
  I: Integer;
begin

//释放创建的对象

  for I := ComponentCount-1 downto 0 do
  begin
    if Components[i] is TButton then
    begin
       TButton(Components[i]).Free;
    end;
  end;
  Action := cafree;
end;

procedure TForm2.WMMOUSEDOWN(var Msg: TWMLButtonDown);
var
 button:TBUtton;
begin
  if msg.msg = WM_LBUTTONDOWN then
  begin
    Button := TButton.Create(Form2);
    button.Parent := Form2;
    button.Left := msg.XPos;
    button.Top  := msg.YPos;
    button.Width := button.Width  + 50;
    button.Caption := Format('button at %d,%d',[msg.XPos,msg.YPos]);
  end;
end;

end.