写一个可拖动的 TShape（简单有效：依靠VCL体系，TShape自己就能被探测到被点击了，然后只要改变Left坐标就行了）

unit Unit2;

interface

uses
Classes, Controls, ExtCtrls;

type
TMyShape = class(TShape)
private
fMouseFlag: Boolean;
fx,fy: Integer;
protected
procedure MouseDown(Button: TMouseButton; Shift: TShiftState; X: Integer;
Y: Integer); override;
procedure MouseUp(Button: TMouseButton; Shift: TShiftState; X: Integer;
Y: Integer); override;
procedure MouseMove(Shift: TShiftState; X: Integer; Y: Integer); override;
end;

implementation

{ TMyShape }

procedure TMyShape.MouseDown(Button: TMouseButton; Shift: TShiftState; X,
Y: Integer);
begin
inherited;
fx := X;
fy := Y;
fMouseFlag := True;
end;

procedure TMyShape.MouseMove(Shift: TShiftState; X, Y: Integer);
begin
inherited;
if fMouseFlag then
begin
Left := Left + X - fx;
Top := Top + Y - fy;
end;
end;

procedure TMyShape.MouseUp(Button: TMouseButton; Shift: TShiftState; X,
Y: Integer);
begin
inherited;
fMouseFlag := False;
end;

end.

unit Unit1;

interface

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

type
TForm1 = class(TForm)
Button1: TButton;
procedure Button1Click(Sender: TObject);
end;

var
Form1: TForm1;

implementation

{$R *.dfm}

uses Unit2;

procedure TForm1.Button1Click(Sender: TObject);
begin
Randomize;
with TMyShape.Create(Self) do begin
Brush.Color := Random($FFFFFF);
Parent := Self;
Left := 10;
Top := 10;
end;
end;

end.