delphi 鼠标拖拽panel

在 Delphi 中实现鼠标拖拽 Panel 的方法如下：

1. 在鼠标按下事件中获取鼠标位置和 Panel 的位置

procedure TForm1.PanelMouseDown(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
begin
  FDragging := True;
  FMousePos := Point(X, Y);
  FPanelPos := Panel1.Left;
end;

2. 在鼠标移动事件中更新 Panel 的位置

procedure TForm1.PanelMouseMove(Sender: TObject; Shift: TShiftState; X,
  Y: Integer);
begin
  if FDragging then
    Panel1.Left := FPanelPos + (X - FMousePos.X);
end;

3. 在鼠标释放事件中停止拖拽

procedure TForm1.PanelMouseUp(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
begin
  FDragging := False;
end;

完整代码如下：

unit Unit1;

interface

uses
  Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
  Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.ExtCtrls;

type
  TForm1 = class(TForm)
    Panel1: TPanel;
    procedure PanelMouseDown(Sender: TObject; Button: TMouseButton;
      Shift: TShiftState; X, Y: Integer);
    procedure PanelMouseMove(Sender: TObject; Shift: TShiftState; X,
      Y: Integer);
    procedure PanelMouseUp(Sender: TObject; Button: TMouseButton;
      Shift: TShiftState; X, Y: Integer);
  private
    FDragging: Boolean;
    FMousePos: TPoint;
    FPanelPos: Integer;
  public
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.PanelMouseDown(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
begin
  FDragging := True;
  FMousePos := Point(X, Y);
  FPanelPos := Panel1.Left;
end;

procedure TForm1.PanelMouseMove(Sender: TObject; Shift: TShiftState; X,
  Y: Integer);
begin
  if FDragging then
    Panel1.Left := FPanelPos + (X - FMousePos.X);
end;

procedure TForm1.PanelMouseUp(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
begin
  FDragging := False;
end;

end.