手勢的應用代碼示例

• 如何為view添加手勢以及對手勢做出響應呢

1. 為view添加手勢首先定義一個手勢對象
   UISwipeGestureRecognizer * recognizer;
   2.給view添加上四種手勢的代碼如下：

• 添加右滑手勢：

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

• 添加左滑手勢：

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

• 添加上滑手勢：

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

• 添加下滑手勢：

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

3. 添加手勢的響應事件:

 - (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");
    }
}