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
, withEvent event: UIEvent?) { } // 触摸移动，重写 UIResponder 中定义的方法 override func touchesMoved(touches: Set , withEvent event: UIEvent?) { } // 触摸结束，重写 UIResponder 中定义的方法 override func touchesEnded(touches: Set , withEvent event: UIEvent?) { } // 触摸取消，重写 UIResponder 中定义的方法 override func touchesCancelled(touches: Set !, 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
, 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
, 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() }