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ios事件-触摸事件3(UIButton 和 pointInSide()、hitTest()、touchesBegan()、touchesMoved()、touchesEnded()、touchesCancelled()的关系)
先看效果图
本文中，凡是看到xxx(),即表示xxx是一个函数或者方法！！！事件分为事件传递和事件响应，其中，事件响应又称事件处理。
具体代码
ButtonVC的代码如下：
代码语言：javascript复制@interface ButtonVC : UIViewController
@end
//--------分隔符，分隔.h文件和.m文件-------------
#import "ButtonVC.h"
#import "MyButton.h"
@interface ButtonVC ()
@end
//--------分隔符，分隔.h文件和.m文件-------------
@implementation ButtonVC
/**
1、button的点击和pointInSide()、hitTest()的关系：在button的hitTest()中返回button实例，这个button才能响应事件
2、button不同事件的识别，也是通过touchesBegan()、touchesMoved()、touchesEnd()和touchesCanceled()来识别，所以如果你在你自定义的button里面的重写的touchesBegan: withEvent:方法中不调用[super touchesBegan:touches withEvent:event];时，button的监听方法（在本例中为clicka:withEvent:方法）就不会被调用！
3、Button的addTarget:action:forControlEvents方法的forControlEvents的参数有UIControlEventTouchUpInside、UIControlEventTouchDown。
其中UIControlEventTouchDown表示@selector(clicka:withEvent:)方法在Button的touchesBegan:withEvent:方法之后以及touchesMoved:withEvent:方法之前调用。
UIControlEventTouchUpInside表示@selector(clicka:withEvent:)方法在Button的touchesEnded:withEvent:方法之后调用。
*/
- (void)viewDidLoad {
[super viewDidLoad];
self.view.backgroundColor = UIColor.whiteColor;
MyButton *button = [MyButton buttonWithType:UIButtonTypeCustom];
button.frame = CGRectMake(100.f, 100.f, 100.f, 100.f);
button.backgroundColor = UIColor.redColor;
[button setTitle:@"一个button" forState:UIControlStateNormal];
[button addTarget:self action:@selector(clicka:withEvent:) forControlEvents:UIControlEventTouchDown]; //添加监听，监听对象是self，监听策略是UIControlEventTouchDown，监听方法是clicka:withEvent:
[button sendActionsForControlEvents:UIControlEventTouchDown];//即使没有[self.view addSubview:button]， 下面的clicka()也会被调用
[self.view addSubview:button];
}
- (void)clicka:(MyButton *)button withEvent:(UIEvent *)event {
NSLog(@"你点击了button");
}
- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event {
NSLog(@"vc, %s", __func__);
[super touchesBegan:touches withEvent:event];
}
- (void)touchesMoved:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event {
NSLog(@"vc, %s", __func__);
[super touchesMoved:touches withEvent:event];
}
- (void)touchesEnded:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event {
NSLog(@"vc, %s", __func__);
[super touchesEnded:touches withEvent:event];
}
- (void)touchesCancelled:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event {
NSLog(@"vc, %s", __func__);
[super touchesCancelled:touches withEvent:event];
}
@endMyButton的代码如下：
代码语言：javascript复制#import <UIKit/UIKit.h>
@interface MyButton : UIButton
@end
//--------分隔符，分隔.h文件和.m文件-------------
@implementation MyButton
- (BOOL)pointInside:(CGPoint)point withEvent:(UIEvent *)event {
NSLog(@"%s", __func__);
return [super pointInside:point withEvent:event];
}
- (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event {
NSLog(@"%s", __func__);
return [super hitTest:point withEvent:event];
}
- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event {
NSLog(@"%s", __func__);
[super touchesBegan:touches withEvent:event];
}
- (void)touchesMoved:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event {
NSLog(@"%s", __func__);
[super touchesMoved:touches withEvent:event];
}
- (void)touchesEnded:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event {
NSLog(@"%s", __func__);
[super touchesEnded:touches withEvent:event];
}
- (void)touchesCancelled:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event {
NSLog(@"%s", __func__);
[super touchesCancelled:touches withEvent:event];
}
@end操作场景
- 进入ButtonVC的界面时，还没有做任何操作，输出结果如下：
2019-08-31 14:58:24.239067 0800 E03事件层次分析[29333:9860811] 你点击了button分析：在ButtonVC的viewDidLoad()中调用了[button sendActionsForControlEvents:UIControlEventTouchDown]; ，该方法会调用监听策略为UIControlEventTouchDown的监听对象的监听方法，在本例中调用的是ButtonVC（监听对象）的clicka: withEvent:方法（监听方法）。
- 在红色按钮的区域内点击一下，输出结果如下：
2019-08-31 15:04:47.589038 0800 E03事件层次分析[29333:9860811] -[MyButton hitTest:withEvent:]
2019-08-31 15:04:47.589239 0800 E03事件层次分析[29333:9860811] -[MyButton pointInside:withEvent:]
2019-08-31 15:04:47.590528 0800 E03事件层次分析[29333:9860811] -[MyButton touchesBegan:withEvent:]
2019-08-31 15:04:47.590724 0800 E03事件层次分析[29333:9860811] 你点击了button
2019-08-31 15:04:47.723649 0800 E03事件层次分析[29333:9860811] -[MyButton touchesEnded:withEvent:]分析：button的UIControlEventTouchDown事件的识别，是通过touchesBegan()来识别。
如果把ButtonVC的viewDidLoad()里面的[button addTarget:self action:@selector(clicka:withEvent:) forControlEvents:UIControlEventTouchDown];改为[button addTarget:self action:@selector(clicka:withEvent:) forControlEvents:UIControlEventTouchUpInside];，然后把MyButton中的[super touchesEnded:touches withEvent:event];删掉，那么 在红色按钮的区域内点击一下，输出结果如下：
2019-08-31 15:08:21.163142 0800 E03事件层次分析[29630:9884894] -[MyButton hitTest:withEvent:]
2019-08-31 15:08:21.163395 0800 E03事件层次分析[29630:9884894] -[MyButton pointInside:withEvent:]
2019-08-31 15:08:21.164825 0800 E03事件层次分析[29630:9884894] -[MyButton touchesBegan:withEvent:]
2019-08-31 15:08:21.241352 0800 E03事件层次分析[29630:9884894] -[MyButton touchesEnded:withEvent:]说明：button的UIControlEventTouchUpInside事件的识别，是通过touchesBegan和touchesEnded()来识别。
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