圖片掌形拖曳工具 (圖片中間有小手)

首先新增
1個TScrollBox; AutoScroll屬性False;
1個TImage; Cursor屬性crHandPoint; Pitcher屬性加入自己的圖片;
1個TScrollBar; Min屬性1; LargeChange屬性10;
1個TScrollBar; Min屬性1; LargeChange屬性10; Kind屬性sbVertical

事件
在兩個TScrollBar物件都點兩下。
TImage的OnMouseDown、OnMouseMove及OnMouseUp都點兩下
TForm的OnCreate

unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    ScrollBox1: TScrollBox;
    Image1: TImage;
    ScrollBar1: TScrollBar;
    ScrollBar2: TScrollBar;
    procedure Image1MouseMove(Sender: TObject; Shift: TShiftState; X,
      Y: Integer);
    procedure Image1MouseDown(Sender: TObject; Button: TMouseButton;
      Shift: TShiftState; X, Y: Integer);
    procedure Image1MouseUp(Sender: TObject; Button: TMouseButton;
      Shift: TShiftState; X, Y: Integer);
    procedure FormCreate(Sender: TObject);
    procedure ScrollBar2Change(Sender: TObject);
    procedure ScrollBar1Change(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

var CanMove:boolean;
    OldX,OldY:Integer;

procedure TForm1.Image1MouseMove(Sender: TObject; Shift: TShiftState; X,
  Y: Integer);
var
  temp:Integer;
begin
  if CanMove then //可以開始移動
  begin

    //往左右移判斷
    temp:=Image1.Left+X-OldX;
    if temp > -1  then
      Image1.Left := -1
    else if temp < ScrollBox1.Width-Image1.Width then
      Image1.Left := ScrollBox1.Width-Image1.Width
    else
      Image1.Left := temp;
    ScrollBar1.Position:=-Image1.Left;

    //往上下移判斷
    temp:=Image1.Top+Y-OldY;
    if temp > -1  then
      Image1.Top := -1
    else if temp < ScrollBox1.Height-Image1.Height then
      Image1.Top := ScrollBox1.Height-Image1.Height
    else
      Image1.Top := temp;
    ScrollBar2.Position:=-Image1.Top;

  end;
end;

procedure TForm1.Image1MouseDown(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
begin
  CanMove:=true; //設定可以開始
  OldX:=X;  //OldX為滑鼠點下去的X位置
  OldY:=Y;  //OldX為滑鼠點下去的Y位置

end;

procedure TForm1.Image1MouseUp(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
begin
  CanMove:=False; //設定不可以開始
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
  ScrollBox1.DoubleBuffered:=True;

  ScrollBar1.Max:=Image1.Width-ScrollBox1.Width+(ScrollBox1.Width*ScrollBox1.Width div Image1.Width);
  ScrollBar1.Pagesize:=ScrollBox1.Width*ScrollBox1.Width div Image1.Width;

  ScrollBar2.Max:=Image1.Height-ScrollBox1.Height+(ScrollBox1.Height*ScrollBox1.Height div Image1.Height);
  ScrollBar2.Pagesize:=ScrollBox1.Height*ScrollBox1.Height div Image1.Height;
end;

procedure TForm1.ScrollBar1Change(Sender: TObject);
begin
  if ScrollBar1.Position > Image1.Width-ScrollBox1.Width then
    ScrollBar1.Position:=Image1.Width-ScrollBox1.Width;
  Image1.Left:=-ScrollBar1.Position;
end;

procedure TForm1.ScrollBar2Change(Sender: TObject);
begin
  if ScrollBar2.Position > Image1.Height-ScrollBox1.Height then
    ScrollBar2.Position:=Image1.Height-ScrollBox1.Height;
  Image1.Top:=-ScrollBar2.Position;
end;

end.