拖动处理

procedure TForm1.edt1MouseDown(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
begin
  if Button=mbLeft then
    (Sender as TEdit).BeginDrag(False) ;    //开始拖动
end;

procedure TForm1.mmo1DragDrop(Sender, Source: TObject; X, Y: Integer);
begin
  if (Sender is TMemo) and (Source is TEdit) then
    (Sender as TMemo).Lines.Add((Source as TEdit).Text)  //拖到目的位置
end;

procedure TForm1.mmo1DragOver(Sender, Source: TObject; X, Y: Integer;
  State: TDragState; var Accept: Boolean);
begin
  if Source is TEdit then
    Accept:=True;     //接收拖动
end;