Delphi 2010 新增功能之: 手势编程[1] - 初识 TGestureManager

Delphi 2010 最抢眼的新功能可能就是支持"触摸屏"了, 它包括一个 可触控的软键盘 和识别不同的触屏手势.

因为手势同时支持鼠标, 所以没有触摸屏的我也可以尝试一下其大多数的功能.

首次尝试的步骤:

1、加 TGestureManager 控件如窗体: GestureManager1;

2、设置窗体属性 Touch.GestureManager := GestureManager1; {下面程序是在设计时指定的属性}

3、添加窗体的 OnGesture 事件, 随便写点什么;

4、然后运行程序, 用鼠标随便在窗体上 "划" 几下... 第一个测试程序完成了!

测试代码:

unit Unit1;

interface

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

type
TForm1 = class(TForm)
GestureManager1: TGestureManager;
procedure FormCreate(Sender: TObject);
procedure FormGesture(Sender: TObject; const EventInfo: TGestureEventInfo;
var Handled: Boolean);
end;

var
Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.FormCreate(Sender: TObject);
begin
Self.Touch.GestureManager := GestureManager1; {可在设计时指定}
end;

procedure TForm1.FormGesture(Sender: TObject;
const EventInfo: TGestureEventInfo; var Handled: Boolean);
begin
ShowMessage(Sender.ClassName + '_Gesture');
end;

end.

现在程序可以 "感知手势" 了, 怎么 "识别手势" 呢?

Delphi 把可以识别的手势分成了 3 类: 标准手势、自定义手势、交互手势(InteractiveGestures).

其中的交互手势用鼠标不好模拟, 可能只能用于触摸屏;

Delphi 预定义了 34 种标准手势, 并定义成 TStandardGesture 枚举类型:

TStandardGesture = (
sgLeft            = sgiLeft,
sgRight           = sgiRight,
sgUp              = sgiUp,
sgDown            = sgiDown,
sgUpLeft          = sgiUpLeft,
sgUpRight         = sgiUpRight,
sgDownLeft        = sgiDownLeft,
sgDownRight       = sgiDownRight,
sgLeftUp          = sgiLeftUp,
sgLeftDown        = sgiLeftDown,
sgRightUp         = sgiRightUp,
sgRightDown       = sgiRightDown,
sgUpDown          = sgiUpDown,
sgDownUp          = sgiDownUp,
sgLeftRight       = sgiLeftRight,
sgRightLeft       = sgiRightLeft,
sgUpLeftLong      = sgiUpLeftLong,
sgUpRightLong     = sgiUpRightLong,
sgDownLeftLong    = sgiDownLeftLong,
sgDownRightLong   = sgiDownRightLong,
sgScratchout      = sgiScratchout,
sgTriangle        = sgiTriangle,
sgSquare          = sgiSquare,
sgCheck           = sgiCheck,
sgCurlicue        = sgiCurlicue,
sgDoubleCurlicue  = sgiDoubleCurlicue,
sgCircle          = sgiCircle,
sgDoubleCircle    = sgiDoubleCircle,
sgSemiCircleLeft  = sgiSemiCircleLeft,
sgSemiCircleRight = sgiSemiCircleRight,
sgChevronUp       = sgiChevronUp,
sgChevronDown     = sgiChevronDown,
sgChevronLeft     = sgiChevronLeft,
sgChevronRight    = sgiChevronRight);

注意: 每个枚举项都对应了一个常数值(譬如: 枚举项 sgLeft 对应 sgiLeft, sgiLeft 是之前定义好的常数);

应记下常数的命名规律, 后面会经常用到它们, 以区别触发的是哪个手势, 譬如:

if EventInfo.GestureID = sgiLeft then ...

下面是从 docwiki.embarcadero.com/RADStudio/en/TStandardGesture_Enum 拷过来的标准手势的图示:

Enum	Symbol
sgLeft
sgRight
sgUp
sgDown
sgUpLeft
sgUpRight
sgDownLeft
sgDownRight
sgLeftUp
sgLeftDown
sgRightUp
sgRightDown
sgUpDown
sgDownUp
sgLeftRight
sgRightLeft
sgUpLeftLong
sgUpRightLong
sgDownLeftLong
sgDownRightLong
sgScratchout
sgTriangle
sgSquare
sgCheck
sgCurlicue
sgDoubleCurlicue
sgCircle
sgDoubleCircle
sgSemiCircleLeft
sgSemiCircleRight
sgChevronUp
sgChevronDown
sgChevronLeft
sgChevronRight