手势的应用代码示例

• 如何为view添加手势以及对手势做出响应呢

1. 为view添加手势首先定义一个手势对象
   UISwipeGestureRecognizer * recognizer;
   2.给view添加上四种手势的代码如下：

• 添加右滑手势：

recognizer = [[UISwipeGestureRecognizer alloc]initWithTarget:self action:@selector(handleSwipeFrom:)];
    [recognizer setDirection:(UISwipeGestureRecognizerDirectionRight)];
    [self.view addGestureRecognizer:recognizer];

• 添加左滑手势：

recognizer = [[UISwipeGestureRecognizer alloc]initWithTarget:self action:@selector(handleSwipeFrom:)];
   [recognizer setDirection:(UISwipeGestureRecognizerDirectionLeft)];
   [self.view addGestureRecognizer:recognizer];

• 添加上滑手势：

recognizer = [[UISwipeGestureRecognizer alloc]initWithTarget:self action:@selector(handleSwipeFrom:)];
    [recognizer setDirection:(UISwipeGestureRecognizerDirectionUp)];
    [self.view addGestureRecognizer:recognizer];

• 添加下滑手势：

recognizer = [[UISwipeGestureRecognizer alloc]initWithTarget:self action:@selector(handleSwipeFrom:)];
    [recognizer setDirection:(UISwipeGestureRecognizerDirectionDown)];
    [self.view addGestureRecognizer:recognizer];

3. 添加手势的响应事件:

 - (void)handleSwipeFrom:(UISwipeGestureRecognizer *)recognizer{
    if(recognizer.direction == UISwipeGestureRecognizerDirectionDown) {
        NSLog(@"swipe down");
    }
    if(recognizer.direction == UISwipeGestureRecognizerDirectionUp) {
        NSLog(@"swipe up");
    }
    if(recognizer.direction == UISwipeGestureRecognizerDirectionLeft) {
        NSLog(@"swipe left");
    }
    if(recognizer.direction == UISwipeGestureRecognizerDirectionRight) { 
      NSLog(@"swipe right");
    }
}