iOS中的触摸事件与响应

- (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event

-(UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event{
    if(self.userInteractionEnabled == NO || self.hidden == YES || self.alpha <= 0.01) {
        return nil;
    }
    
    if (![self pointInside:point withEvent:event]) {
        return nil;
    }

    int count = (int)self.subviews.count;
    for (int i = count - 1; i >= 0; i--) {
        UIView *chileV =  self.subviews[i];
        CGPoint childP = [self convertPoint:point toView:chileV];
        UIView *fitView = [chileV hitTest:childP withEvent:event];
        if(fitView){
            return fitView;
        }
    }
    
    return self;
    
}

//手指接触屏幕时
- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event

//手指在屏幕上移动时
- (void)touchesMoved:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event

//手指离开屏幕时
- (void)touchesEnded:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event

//触摸被系统中断时，例如来电，锁屏等
- (void)touchesCancelled:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event

///事件传来时(iOS13.4之后加入，暂时不知道它的具体作用)
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveEvent:(UIEvent *)event

///触摸传来时
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch

///手势即将识别
- (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer

Controls communicate directly with their associated target object using action messages. 
When the user interacts with a control, the control sends an action message to its target object. 
Action messages are not events, but they may still take advantage of the responder chain. 
When the target object of a control is nil, UIKit starts from the target object and traverses the responder chain until it finds an object that implements the appropriate action method. 
For example, the UIKit editing menu uses this behavior to search for responder objects that implement methods with names like cut(_:), copy(_:), or paste(_:).

Gesture recognizers receive touch and press events before their view does. 
If a view's gesture recognizers fail to recognize a sequence of touches, UIKit sends the touches to the view. 
If the view does not handle the touches, UIKit passes them up the responder chain. 
For more information about using gesture recognizer’s to handle events, see Handling UIKit Gestures.

Unhandled events are passed from responder to responder in the active responder chain, 
which is the dynamic configuration of your app’s responder objects. 
Figure 1 shows the responders in an app whose interface contains a label,
a text field, a button, and two background views.
The diagram also shows how events move from one responder to the next, following the responder chain.
If the text field does not handle an event, UIKit sends the event to the text field’s parent UIView object, followed by the root view of the window. 
From the root view, the responder chain diverts to the owning view controller before directing the event to the window.
If the window cannot handle the event, UIKit delivers the event to the UIApplication object, and possibly to the app delegate if that object is an instance of UIResponder and not already part of the responder chain.

    UIView *view0 = [[UIView alloc]init];
    view0.backgroundColor = [UIColor blackColor];
    UITapGestureRecognizer *tap1 = [[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(touchAction)];
    [view0 addGestureRecognizer:tap1];

    [self.view addSubview:view0];
    [view0 mas_makeConstraints:^(MASConstraintMaker *make) {
        make.center.mas_equalTo(self.view);
        make.width.height.mas_equalTo(500);
    }];
    
    UIView *view1 = [[UIView alloc]init];
    view1.backgroundColor = [UIColor grayColor];
    [view0 addSubview:view1];
    [viewB1 mas_makeConstraints:^(MASConstraintMaker *make) {
        make.center.mas_equalTo(self.view);
        make.width.height.mas_equalTo(80);
    }];

    UIButton *btn = [[UIButton alloc]init];
    [btn addTarget:nil action:@selector(btnTouchAction) forControlEvents:UIControlEventTouchUpInside];
    btn.backgroundColor = [UIColor greenColor];
    [self.view addSubview:btn];
    [btn mas_makeConstraints:^(MASConstraintMaker *make) {
        make.center.mas_equalTo(self.view);
        make.width.height.mas_equalTo(50);
    }];

- (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer

- (void)touchesCancelled:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event

- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer{
    return  true;
}