iOS 上下左右手勢識別

- (void)viewDidLoad {  //建立滑動手勢    UISwipeGestureRecognizer *recognizer;       recognizer = [[UISwipeGestureRecognizer alloc] initWithTarget:selfaction:@selector(handleSwipeFrom:)];   //設定滑動方向，下面以此類推    [recognizer setDirection:(UISwipeGestureRecognizerDirectionRight)];       [[self view] addGestureRecognizer:recognizer];       [recognizer release];        recognizer = [[UISwipeGestureRecognizer alloc] initWithTarget:selfaction:@selector(handleSwipeFrom:)];       [recognizer setDirection:(UISwipeGestureRecognizerDirectionUp)];       [[self view] addGestureRecognizer:recognizer];       [recognizer release];             recognizer = [[UISwipeGestureRecognizer alloc] initWithTarget:selfaction:@selector(handleSwipeFrom:)];       [recognizer setDirection:(UISwipeGestureRecognizerDirectionDown)];      [[self view] addGestureRecognizer:recognizer];       [recognizer release];             recognizer = [[UISwipeGestureRecognizer alloc] initWithTarget:selfaction:@selector(handleSwipeFrom:)];       [recognizer setDirection:(UISwipeGestureRecognizerDirectionLeft)];       [[self view] addGestureRecognizer:recognizer];       [recognizer release];        [super viewDidLoad];   }    //這個是協議回調，所以需要遵循 UIGestureRecognizerDelegate協議-(void)handleSwipeFrom:(UISwipeGestureRecognizer *)recognizer {        NSLog(@"Swipe received.");    www.2cto.com     if (recognizer.direction==UISwipeGestureRecognizerDirectionDown) {                   NSLog(@"向下滑動");      //執行程式       }       if (recognizer.direction==UISwipeGestureRecognizerDirectionUp) {       NSLog(@"向上滑動");      //執行程式       }       if (recognizer.direction==UISwipeGestureRecognizerDirectionLeft) {       NSLog(@"向左滑動");      //執行程式       }       if (recognizer.direction==UISwipeGestureRecognizerDirectionRight) {       NSLog(@"向右滑動");      //執行程式       }  }