iOS基础篇（十七）——UIGestureRecognizer用法

UIGestureRecognizer（手势识别）在iOS 中非常重要，他极大地提高了移动设备的使用便捷性；

在3.2之前是主要使用的是由UIResponder而来的如下4种方式：

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
 - (void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event
 - (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
 - (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event

但是由于这种方式需要自己计算做不同的手势分辨，实在麻烦。

在3.2 以后，提供了一些常用的手势（UIGestureRecognizer 的子类），开发者可以直接使用他们进行手势操作。

1、拍击——UITapGestureRecognizer 

2、向里或向外捏——UIPinchGestureRecognizer  

3、摇动或者拖拽——UIPanGestureRecognizer  

4、擦碰——UISwipeGestureRecognizer 

5、旋转——UIRotationGestureRecognizer 

6、长按——UILongPressGestureRecognizer 

 

每个手势识别器的用法都差不多，以UITapGestureRecognizer为例：

1     //创建手势识别器对象并监听手势的触发
2     UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tapAction:)];
3     //连续敲击次数
4     tap.numberOfTapsRequired = 2;
5     //需要两根手指一起敲击
6     tap.numberOfTouchesRequired = 2;
7     //添加手势到指定的view上
8     [self.view addGestureRecognizer:tap];

敲击实例：

1、UITapGestureRecognizer 拍击

 1 //创建手势识别器对象并监听手势的触发
 2     UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tapAction:)];
 3     //连续敲击次数
 4     tap.numberOfTapsRequired = 2;
 5     //需要两根手指一起敲击
 6     tap.numberOfTouchesRequired = 2;
 7     //添加手势到指定的view上
 8     [self.view addGestureRecognizer:tap];
 9 
10 - (void)tapAction:(UITapGestureRecognizer*)tapGesture{
11     
12     NSLog(@"我敲击了屏幕");
13 
14     CGPoint point = [tapGesture locationInView:self.view];
15     NSLog(@"tapAction:%f,%f",point.x,point.y);
16 }

输出：

2、UIPinchGestureRecognizer  向里或向外捏

1     UIPinchGestureRecognizer *Pinch =[[UIPinchGestureRecognizer alloc] initWithTarget:self action:@selector(PinchAction:)];
2     Pinch.delegate = self;
3     [imageView addGestureRecognizer:Pinch];
4     
5 - (void)PinchAction:(UIPinchGestureRecognizer*)pinchGesture{
6         pinchGesture.view.transform = CGAffineTransformScale(pinchGesture.view.transform, pinchGesture.scale, pinchGesture.scale);
7         pinchGesture.scale = 1;
8 }

3、UIPanGestureRecognizer  摇动或者拖拽

//先放置一张图片实施拖拽

   imageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"u=3971024035,4095552302&fm=21&gp=0"]];

    [imageView setFrame:(CGRect){50,50,100,100}];

    [self.view addSubview:imageView];

    UIPanGestureRecognizer *pan = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(panAction:)];
    pan.delegate = self;
    [self.view addGestureRecognizer:pan];
    
    //设置触发拖拽的最少触摸点,默认为1
    pan.minimumNumberOfTouches = 1;
    //设置触发拖拽的最多触摸点
    pan.maximumNumberOfTouches = 1;


- (void)panAction:(UIPanGestureRecognizer *)panGesture{
    CGPoint point = [panGesture locationInView:self.view];
    
    NSLog(@"panAction:(%f, %f)",point.x, point.y);
    imageView.center = point;
    
    if (panGesture.state==UIGestureRecognizerStateBegan) {
        NSLog(@"panAction StateBegan:(%f,%f)", point.x, point.y);
    }

    if (panGesture.state==UIGestureRecognizerStateChanged) {
        NSLog(@"panAction StateChanged:(%f,%f)", point.x, point.y);
    }
    
    if (panGesture.state==UIGestureRecognizerStateEnded) {
        NSLog(@"panAction StateEnded:(%f,%f)", point.x, point.y);
    }
    
}

输出：

4、UISwipeGestureRecognizer  擦碰

 1     UISwipeGestureRecognizer *leftSwipeGesture = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(SwipeAction:)];
 2     [self.view addGestureRecognizer:leftSwipeGesture];
 3     leftSwipeGesture.direction = UISwipeGestureRecognizerDirectionLeft;
 4     
 5     UISwipeGestureRecognizer *rightSwipeGesture = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(SwipeAction:)];
 6     [self.view addGestureRecognizer:rightSwipeGesture];
 7     rightSwipeGesture.direction = UISwipeGestureRecognizerDirectionRight;
 8     
 9 - (void)SwipeAction:(UISwipeGestureRecognizer*)swipeGesture{
10     if (swipeGesture.direction==UISwipeGestureRecognizerDirectionLeft) {
11         NSLog(@"swipeGesture:Left");
12     }
13     if (swipeGesture.direction==UISwipeGestureRecognizerDirectionRight) {
14         NSLog(@"swipeGesture:Right");
15     }
16 }

输出：

 

5、UIRotationGestureRecognizer  旋转

 1 UIRotationGestureRecognizer *rotations = [[UIRotationGestureRecognizer alloc] initWithTarget:self action:@selector(rotationAction:)];
 2     rotations.delegate = self;
 3     rotation = 0;
 4     [self.view addGestureRecognizer:rotations];
 5 
 6 - (void)rotationAction:(UIRotationGestureRecognizer*)rotationGesture{
 7     imageView.transform = CGAffineTransformMakeRotation(rotation+rotationGesture.rotation);
 8     
 9     if (rotationGesture.state==UIGestureRecognizerStateEnded) {
10         rotation += rotationGesture.rotation;
11     }
12 
13 }

 

6、UILongPressGestureRecognizer  长按

 1     UILongPressGestureRecognizer *longp = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(longAction:)];
 2     [self.view addGestureRecognizer:longp];
 3     
 4     longp.numberOfTouchesRequired = 1;
 5     //长按时间为2秒
 6     longp.minimumPressDuration = 2;
 7     //允许15秒中运动
 8     longp.allowableMovement = 15;
 9 
10 - (void)longAction:(UILongPressGestureRecognizer *)longPress{
11     CGPoint point = [longPress locationInView:self.view];
12     imageView.center = point;
13 
14     if(longPress.state == UIGestureRecognizerStateBegan){
15         NSLog(@"longAction StateBegan: (%f, %f)", point.x, point.y);
16     }
17     
18     if(longPress.state == UIGestureRecognizerStateEnded){
19         NSLog(@"longAction StateEnded: (%f, %f)", point.x, point.y);
20     }
21 }

输出：

 

转载于:https://www.cnblogs.com/0320y/p/5075608.html