iOS GestureRecognizer与UIResponde

2018-07-30 本文已影响66人 taosiyu

在iOS中UIView是继承于UIResponder的，而UIResponder是专门用来响应用户的操作处理各种事件的，包括触摸事件(Touch Events)、运动事件(Motion Events)、远程控制事件(Remote Control Events,如插入耳机调节音量触发的事件)，而很多我们常用的类也继承于UIResponder(UIApplication、UIView、UIViewController).

而以下几个方法

@interface UIResponder : NSObject
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event;//触摸屏幕
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event;//在屏幕上移动
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event;//离开屏幕
- (void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event;

是响应触摸事件的方法，我们可以利用这几个方法自定义自己的手势。当然Apple也为我们提供了几个基础的封装的手势提供使用（了UIGestureRecognizer手势识别）

这里并不深入研究手势的响应和传递，而是研究下几个基础的手势和touchs的关系，这里主要利用这几个内置的手势方法：

UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(tapEvent:)];
[self addGestureRecognizer:tap];//点击

UIPanGestureRecognizer *pan = [[UIPanGestureRecognizer alloc]initWithTarget:self action:@selector(tapEvent:)];
[self addGestureRecognizer:pan];//平移，慢速移动

UISwipeGestureRecognizer *swipe = [[UISwipeGestureRecognizer alloc]initWithTarget:self action:@selector(tapEvent:)];//滑动，快速移动
[self addGestureRecognizer:swipe];

UILongPressGestureRecognizer *longG = [[UILongPressGestureRecognizer alloc]initWithTarget:self action:@selector(tapEvent:)];//长按
[self addGestureRecognizer:longG];