事件处理详解
一：事件处理
事件处理常见属性：
事件类型
- @property(nonatomic,readonly) UIEventType type;
- @property(nonatomic,readonly) UIEventSubtype subtype;
事件产生的时间
- @property(nonatomic,readonly) NSTimeInterval timestamp;
事件传递
– hitTest:withEvent:
SWIFT
func hitTest(_ point: CGPoint, withEvent event: UIEvent?) -> UIView?
OBJECTIVE-C
- (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event
– pointInside:withEvent:
SWIFT
func pointInside(_ point: CGPoint, withEvent event: UIEvent?) -> a href="" rel="external nofollow" Bool /a
OBJECTIVE-C
- (BOOL)pointInside:(CGPoint)pointwithEvent:(UIEvent *)event
事件传递方法的简单实用：
事件传递的时候调用
- 什么时候调用:当事件传递给控件的时候，就会调用控件的这个方法，去寻找最合适的view
- 作用：寻找最合适的view
// point：当前的触摸点，point这个点的坐标系就是方法调用者
- (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event { // 调用系统的做法去寻找最合适的view，返回最合适的view UIView *fitView = [super hitTest:point withEvent:event]; // NSLog(@"fitView--%@",fitView); return fitView; }
// 作用：判断当前这个点在不在方法调用者（控件）上
- (BOOL)pointInside:(CGPoint)point withEvent:(UIEvent *)event { return YES; }
事件传递底层的实现：
如果父控件不能接收触摸事件，那么子控件就不可能接收到触摸事件(掌握)
- 如何找到最合适的控件来处理事件？
- 自己是否能接收触摸事件？
- 触摸点是否在自己身上？
- 从后往前遍历子控件数组，重复前面的两个步骤
- 如果没有符合条件的子控件，那么就自己最适合处理
// 点击黄色视图 -》 事件 -》 UIApplication -> UIWindow
// 因为所有的视图类都是继承BaseView
- (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event { NSLog(@"%@--hitTest",[self class]); // return [super hitTest:point withEvent:event]; // 1.判断当前控件能否接收事件 if (self.userInteractionEnabled == NO || self.hidden == YES || self.alpha <= 0.01) return nil; // 2. 判断点在不在当前控件 if ([self pointInside:point withEvent:event] == NO) return nil; // 3.从后往前遍历自己的子控件 NSInteger count = self.subviews.count; ; i >= ; i--) { UIView *childView = self.subviews[i]; // 把当前控件上的坐标系转换成子控件上的坐标系 CGPoint childP = [self convertPoint:point toView:childView]; UIView *fitView = [childView hitTest:childP withEvent:event]; if (fitView) { // 寻找到最合适的view return fitView; } } // 循环结束,表示没有比自己更合适的view return self; }
关于事件传递的底层原理和方法的实现：
事件响应：（响应者链）
响应者链条：是由多个响应者对象连接起来的链条
作用：能很清楚的看见每个响应者之间的联系，并且可以让一个事件多个对象处理。
响应者对象：能处理事件的对象
事件传递的完整过程
- 1> 先将事件对象由上往下传递(由父控件传递给子控件)，找到最合适的控件来处理这个事件。
- 2> 调用最合适控件的touches….方法
- 3> 如果调用了[super touches….];就会将事件顺着响应者链条往上传递，传递给上一个响应者
- 4> 接着就会调用上一个响应者的touches….方法
重点：如何判断上一个响应者
- 1> 如果当前这个view是控制器的view,那么控制器就是上一个响应者
- 2> 如果当前这个view不是控制器的view,那么父控件就是上一个响应者
二：触摸事件
各个方法的解释
UITouch相关属性：
触摸产生时所处的窗口
- @property(nonatomic,readonly,retain) UIWindow *window;
触摸产生时所处的视图
- @property(nonatomic,readonly,retain) UIView *view;
短时间内点按屏幕的次数，可以根据tapCount判断单击、双击或更多的点击
- @property(nonatomic,readonly) NSUInteger tapCount;
记录了触摸事件产生或变化时的时间，单位是秒
- @property(nonatomic,readonly) NSTimeInterval timestamp;
当前触摸事件所处的状态
- @property(nonatomic,readonly) UITouchPhase phase;
方法：
- – (CGPoint)locationInView:(UIView *)view;
- 返回值表示触摸在view上的位置
- 这里返回的位置是针对view的坐标系的（以view的左上角为原点(0, 0)）
- 调用时传入的view参数为nil的话，返回的是触摸点在UIWindow的位置
- – (CGPoint)previousLocationInView:(UIView *)view;
该方法记录了前一个触摸点的位置
UIView不接收触摸事件的三种情况
不接收用户交互
- userInteractionEnabled = NO
隐藏
- hidden = YES
透明
- alpha = 0.0 ~ 0.01
提示：UIImageView的userInteractionEnabled默认就是NO，因此UIImageView以及它的子控件默认是不能接收触摸事件的
实现UIView的拖动：
OC&Swift版
-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event { UITouch *touch = [touches anyObject]; CGPoint curP = [touch locationInView:self]; CGPoint preP = [touch previousLocationInView:self]; CGFloat offsetX = preP.x - curP.x; CGFloat offsetY = preP.y - curP.y; self.transform = CGAffineTransformTranslate(self.transform, -offsetX, -offsetY); } }
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override func touchesMoved(touches: Set<NSObject>, withEvent event: UIEvent) { var touch:UITouch = touches(AnyObject) var preP:CGPoint = touch.locationInView(self) var curP:CGPoint = touch.previousLocationInView(self) var ofX = curP.x - preP.x var ofY = curP.y - preP.y self.transform = CGAffineTransformTranslate(self.transform, ofX, ofY) }
触摸事件简单介绍：
// 当手指开始触摸view
// NSArray,字典，NSSet(无序)
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event { NSLog(@"%ld", touches.count); NSLog(@"%s",__func__); }
// 当手指在view上移动的时候
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event { NSLog(@"%s",__func__); }
// 当手指离开这个view的时候
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event{ NSLog(@"%s",__func__); }
// 当触摸事件被打断的时候调用(电话打入)
- (void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event { }
三：gestureReginazation
各个方法的解释
UIView拖动
OC&Swift版
@interface ViewController () @property (weak, nonatomic) IBOutlet iCocosView *dragView; @end @implementation ViewController - (void)viewDidLoad { [super viewDidLoad]; // self.view.transform = CGAffineTransformTranslate(self.view.transform, 100, 100); /** 为对应的View创建并且添加手势和手势监听方法 */ UIPanGestureRecognizer *pan = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(Drag:)]; [self.dragView addGestureRecognizer:pan]; }
/**
* 实现手势监听方法
*/
-(void)Drag:(UIPanGestureRecognizer *)pan { //获取盘的位置 CGPoint p = [pan translationInView:pan.view]; /** * 使用三步法实现赋值 */ //根据pan的位置获取pan的中心点 CGPoint center = pan.view.center; center.x += p.x; center.y += p.y; pan.view.center = center; //根据pan的移动设置对应View的移动 [pan setTranslation:CGPointZero inView:pan.view]; }
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@IBOutlet weak var dragViews: iCocos! override func viewDidLoad() { super.viewDidLoad() var pan:UIPanGestureRecognizer = UIPanGestureRecognizer(target: self, action: "Drag:") self.dragViews.addGestureRecognizer(pan) } func Drag(pan:UIPanGestureRecognizer) { var P:CGPoint = pan.translationInView(pan.view!) var center:CGPoint = pan.view!.center center.x += P.x center.y += P.y pan.view?.center = center pan.setTranslation(CGPointZero, inView: pan.view)
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手势方法简单实用：UIGestureRecognizerDelegate
#pragma mark – 手势代理方法
// 是否允许开始触发手势
//- (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer //{ // return NO; //}
// 是否允许同时支持多个手势，默认是不支持多个手势
// 返回yes表示支持多个手势
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer { return YES; }
// 是否允许接收手指的触摸点
//- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch{ // // 获取当前的触摸点 // CGPoint curP = [touch locationInView:self.imageView]; // // if (curP.x < self.imageView.bounds.size.width * 0.5) { // return NO; // }else{ // return YES; // } //}
#pragma mark – 点按手势
- (void)setUpTap { // 创建点按手势 UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tap:)]; tap.delegate = self; [_imageView addGestureRecognizer:tap]; } - (void)tap:(UITapGestureRecognizer *)tap { NSLog(@"%s",__func__); }
#pragma mark – 长按手势
// 默认会触发两次 - (void)setUpLongPress { UILongPressGestureRecognizer *longPress = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(longPress:)]; [self.imageView addGestureRecognizer:longPress]; } - (void)longPress:(UILongPressGestureRecognizer *)longPress { if (longPress.state == UIGestureRecognizerStateBegan) { NSLog(@"%s",__func__); } }
#pragma mark – 清扫
- (void)setUpSwipe { // 默认轻扫的方向是往右 UISwipeGestureRecognizer *swipe = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(swipe)]; swipe.direction = UISwipeGestureRecognizerDirectionUp; [self.imageView addGestureRecognizer:swipe]; // 如果以后想要一个控件支持多个方向的轻扫，必须创建多个轻扫手势，一个轻扫手势只支持一个方向 // 默认轻扫的方向是往右 UISwipeGestureRecognizer *swipeDown = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(swipe)]; swipeDown.direction = UISwipeGestureRecognizerDirectionDown; [self.imageView addGestureRecognizer:swipeDown]; } - (void)swipe { NSLog(@"%s",__func__); }
#pragma mark – 旋转手势
- (void)setUpRotation { UIRotationGestureRecognizer *rotation = [[UIRotationGestureRecognizer alloc] initWithTarget:self action:@selector(rotation:)]; rotation.delegate = self; [self.imageView addGestureRecognizer:rotation]; } // 默认传递的旋转的角度都是相对于最开始的位置 - (void)rotation:(UIRotationGestureRecognizer *)rotation { self.imageView.transform = CGAffineTransformRotate(self.imageView.transform, rotation.rotation); // 复位 rotation.rotation = ; // 获取手势旋转的角度 NSLog(@"%f",rotation.rotation); }
#pragma mark – 捏合
- (void)setUpPinch { UIPinchGestureRecognizer *pinch = [[UIPinchGestureRecognizer alloc] initWithTarget:self action:@selector(pinch:)]; pinch.delegate = self; [self.imageView addGestureRecognizer:pinch]; } - (void)pinch:(UIPinchGestureRecognizer *)pinch { self.imageView.transform = CGAffineTransformScale(self.imageView.transform, pinch.scale, pinch.scale); // 复位 pinch.scale = ; }
#pragma mark – 拖拽
- (void)setUpPan { UIPanGestureRecognizer *pan = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(pan:)]; [self.imageView addGestureRecognizer:pan]; } - (void)pan:(UIPanGestureRecognizer *)pan { // 获取手势的触摸点 CGPoint curP = [pan locationInView:self.imageView]; // 移动视图 // 获取手势的移动，也是相对于最开始的位置 CGPoint transP = [pan translationInView:self.imageView]; self.imageView.transform = CGAffineTransformTranslate(self.imageView.transform, transP.x, transP.y); // 复位 [pan setTranslation:CGPointZero inView:self.imageView]; NSLog(@"%@",NSStringFromCGPoint(curP)); }
手势状态：
statetypedef NS_ENUM(NSInteger, UIGestureRecognizerState) { // 没有触摸事件发生，所有手势识别的默认状态 UIGestureRecognizerStatePossible, // 一个手势已经开始但尚未改变或者完成时 UIGestureRecognizerStateBegan, // 手势状态改变 UIGestureRecognizerStateChanged, // 手势完成 UIGestureRecognizerStateEnded, // 手势取消，恢复至Possible状态 UIGestureRecognizerStateCancelled, // 手势失败，恢复至Possible状态 UIGestureRecognizerStateFailed, // 识别到手势识别 UIGestureRecognizerStateRecognized = UIGestureRecognizerStateEnded };
四：加速计：（运动）
- (void)orientationChanged:(NSNotification *)notification { // Respond to changes in device orientation }
- (void)motionEnded:(UIEventSubtype)motion withEvent:(UIEvent *)event { if (motion == UIEventSubtypeMotionShake) { // User was shaking the device. Post a notification named "shake." [[NSNotificationCenter defaultCenter] postNotificationName:@"shake" object:self]; } }
五：远程控制
注册：
MPRemoteCommandCenter *commandCenter = [MPRemoteCommandCenter sharedCommandCenter]; [commandCenter.playCommand addTargetUsingBlock:^(MPRemoteCommandEvent *event) { // Begin playing the current track. [[MyPlayer sharedPlayer] play]; }
使用
- (void)configureNowPlayingInfo:(MPMediaItem*)item{ MPNowPlayingInfoCenter* info = [MPNowPlayingInfoCenter defaultCenter]; NSMutableDictionary* newInfo = [NSMutableDictionary dictionary]; NSSet* itemProperties = [NSSet setWithObjects:MPMediaItemPropertyTitle, MPMediaItemPropertyArtist, MPMediaItemPropertyPlaybackDuration, MPNowPlayingInfoPropertyElapsedPlaybackTime, nil]; [item enumerateValuesForProperties:itemProperties usingBlock:^(NSString *property, id value, BOOL *stop) { [newInfo setObject:value forKey:property]; }]; info.nowPlayingInfo = newInfo; }
