急：如何实现运行时拖动组件？

Question

如题

Answer 1

unit Unit1;interfaceuses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;type
  TForm1 = class(TForm)
    Button1: TButton;
    Button2: TButton;
    Button3: TButton;
    procedure FormCreate(Sender: TObject);
  private
    procedure AppMessage(var Msg: TMsg; var Handled: Boolean);
    { Private declarations }
  public
    { Public declarations }
  end;var
  Form1: TForm1;implementation{$R *.dfm}procedure TForm1.AppMessage(var Msg: TMsg; var Handled: Boolean);
const
  SC_DragMove = $F012;
begin
  if Msg.message = WM_MOUSEMOVE then
  begin
    ReleaseCapture;
    ActiveControl.Perform(WM_SysCommand, SC_DRAGMOVE, 0);
  end
  else if Msg.message = WM_LBUTTONDOWN then
  begin
    ActiveControl:=nil;
  end;
end;procedure TForm1.FormCreate(Sender: TObject);
begin
  Application.OnMessage:=AppMessage;
end;end.