前言
NS_CLASS_AVAILABLE_IOS(2_0) @interface UITouch : NSObject
@available(iOS 2.0, *) public class UITouch : NSObject
- 触摸事件基本都是发生在 viewController 中，首先触摸的对象是视图，而视图的类 UIView 继承了 UIRespnder 类，但是要对事件作出处理，还需要重写 UIResponder 类中定义的事件处理函数。根据不同的触摸状态，程序会调用相应的处理函数。
1、touch 的创建
在系统触摸事件处理方法中实现
Objective-C
// 获取任意一个触摸对象
UITouch *touch = [touches anyObject]; // 获取任意一个触摸对象
UITouch *touch = [[event allTouches] anyObject]; // 获取指定的 view 触摸对象
UITouch *touch = [[event touchesForView:myView] anyObject]; // 获取指定的 window 触摸对象
UITouch *touch = [[event touchesForWindow:self.view.window] anyObject];
Swift
// 获取任意一个触摸对象
let touch:UITouch = touches.first! as UITouch // 获取任意一个触摸对象
let touch2:UITouch = (event?.allTouches()?.first!)! as UITouch // 获取指定的 view 触摸对象
let touch3:UITouch = (event!.touchesForView(myView!)?.first)! as UITouch // 获取指定的 window 触摸对象
let touch4:UITouch = (event!.touchesForWindow(self.view.window!)?.first)! as UITouch
2、touch 的设置
在系统触摸事件处理方法中实现
Objective-C
// 设置接收多点触摸
/*
默认为 NO，即视图默认不接收多点触摸
*/
self.view.multipleTouchEnabled = YES;
Swift
// 设置接收多点触摸
/*
默认为 NO，即视图默认不接收多点触摸
*/
self.view.multipleTouchEnabled = true
3、touch 的获取
在系统触摸事件处理方法中实现
Objective-C
// 获取触摸窗口
UIWindow *touchWindow = touch.window; // 获取触摸视图
UIView *touchView = touch.view; // 获取触摸手势
NSArray *touchGesture = touch.gestureRecognizers; // 获取触摸次数
NSUInteger tapCount = touch.tapCount; // 获取触摸时间
NSTimeInterval timestamp = touch.timestamp; // 获取触摸状态
/*
UITouchPhaseBegan, // whenever a finger touches the surface. 触摸开始
UITouchPhaseMoved, // whenever a finger moves on the surface. 接触点移动
UITouchPhaseStationary, // whenever a finger is touching the surface but hasn't moved
// since the previous event. 接触点无移动
UITouchPhaseEnded, // whenever a finger leaves the surface. 触摸结束
UITouchPhaseCancelled, // whenever a touch doesn't end but we need to stop tracking
// (e.g. putting device to face) 触摸取消
*/
UITouchPhase touchPhase = touch.phase; // 获取触摸位置 // 上次触摸点的位置
CGPoint lastPoint = [touch previousLocationInView:self.view]; // 当前触摸点的位置
CGPoint currentPoint = [touch locationInView:self.view]; // 获取触摸半径
CGFloat majorRadius = touch.majorRadius;
CGFloat majorRadiusTolerance = touch.majorRadiusTolerance;
Swift
// 获取触摸窗口
let touchWindow:UIWindow = touch.window! // 获取触摸视图
let touchView:UIView = touch.view! // 获取触摸手势
let touchGesture:[AnyObject] = touch.gestureRecognizers! // 获取触摸次数
let tapCount:Int = touch.tapCount // 获取触摸时间
let timestamp:NSTimeInterval = touch.timestamp // 获取触摸状态
/*
case Began, // whenever a finger touches the surface. 触摸开始
case Moved, // whenever a finger moves on the surface. 接触点移动
case Stationary, // whenever a finger is touching the surface but hasn't moved since
// the previous event. 接触点无移动
case Ended, // whenever a finger leaves the surface. 触摸结束
case Cancelled, // whenever a touch doesn't end but we need to stop tracking
// (e.g. putting device to face) 触摸取消
*/
let touchPhase:UITouchPhase = touch.phase // 获取触摸位置 // 上次触摸点的位置
let lastPoint:CGPoint = touch.previousLocationInView(self.view) // 当前触摸点的位置
let currentPoint:CGPoint = touch.locationInView(self.view) // 获取触摸半径
let majorRadius:CGFloat = touch.majorRadius
let majorRadiusTolerance:CGFloat = touch.majorRadiusTolerance
4、系统触摸事件处理方法
不用手动调用
Objective-C
// 触摸开始，重写 UIResponder 中定义的方法
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event { } // 触摸移动，重写 UIResponder 中定义的方法
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event { } // 触摸结束，重写 UIResponder 中定义的方法
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event { } // 触摸取消，重写 UIResponder 中定义的方法
- (void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event { }
Swift
// 触摸开始，重写 UIResponder 中定义的方法
override func touchesBegan(touches: Set<UITouch>, withEvent event: UIEvent?) { } // 触摸移动，重写 UIResponder 中定义的方法
override func touchesMoved(touches: Set<UITouch>, withEvent event: UIEvent?) { } // 触摸结束，重写 UIResponder 中定义的方法
override func touchesEnded(touches: Set<UITouch>, withEvent event: UIEvent?) { } // 触摸取消，重写 UIResponder 中定义的方法
override func touchesCancelled(touches: Set<UITouch>!, withEvent event: UIEvent!) { }
5、视图随触摸移动
Objective-C
// 触摸移动
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event { // 获取触摸对象
UITouch *touch = [touches anyObject];
UIView *tapView = touch.view; // 获取触摸点位置
CGPoint lastPoint = [touch previousLocationInView:self.view];
CGPoint currentPoint = [touch locationInView:self.view]; // 改变视图中心坐标
CGPoint tapViewCenter = tapView.center; tapViewCenter.x += currentPoint.x - lastPoint.x;
tapViewCenter.y += currentPoint.y - lastPoint.y; tapView.center = tapViewCenter;
}
Swift
// 触摸移动
override func touchesMoved(touches: Set<UITouch>, withEvent event: UIEvent?) { // 获取触摸对象
let touch:UITouch = touches.first! as UITouch
let tapView = touch.view // 获取触摸点位置
let lastPoint:CGPoint = touch.previousLocationInView(self.view)
let currentPoint:CGPoint = touch.locationInView(self.view) // 改变视图中心坐标
var tapViewCenter = tapView!.center tapViewCenter.x += currentPoint.x - lastPoint.x
tapViewCenter.y += currentPoint.y - lastPoint.y tapView!.center = tapViewCenter
}
6、单击／双击触摸
Objective-C
// 触摸结束
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event { UITouch *touch = [touches anyObject]; // 单击
if (touch.tapCount == 1) { // 响应单击触摸事件
[self performSelector:@selector(singleTapClick) withObject:nil afterDelay:0];
}
// 双击
else if (touch.tapCount == 2) { // 取消单击触摸响应事件
[NSObject cancelPreviousPerformRequestsWithTarget:self selector:@selector(singleTapClick) object:nil]; // 响应双击触摸事件
[self performSelector:@selector(doubleTapClick) withObject:nil afterDelay:0];
}
} // 单击触摸响应事件处理
- (void)singleTapClick { self.view.backgroundColor = [UIColor greenColor];
} // 双击触摸响应事件处理
- (void)doubleTapClick { self.view.backgroundColor = [UIColor orangeColor];
}
Swift
// 触摸结束
override func touchesEnded(touches: Set<UITouch>, withEvent event: UIEvent?) { let touch = touches.first! as UITouch // 单击
if touch.tapCount == 1 { // 响应单击触摸事件
self.performSelector(#selector(singleTapClick), withObject: nil, afterDelay: 0)
} // 双击
if touch.tapCount == 2 { // 取消单击触摸响应事件
NSObject.cancelPreviousPerformRequestsWithTarget(self, selector: #selector(singleTapClick), object: nil) // 响应双击触摸事件
self.performSelector(#selector(doubleTapClick), withObject: nil, afterDelay: 0)
}
} // 单击触摸响应事件处理
func singleTapClick() { self.view.backgroundColor = UIColor.greenColor()
} // 双击触摸响应事件处理
func doubleTapClick() { self.view.backgroundColor = UIColor.orangeColor()
}