IOS 开发学习二十三 手势 切换UIView

#pragma mark 手势-(void)gesture{    UISwipeGestureRecognizer* leftSwipeGestureRecognizer = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(handleSwipes:)];    UISwipeGestureRecognizer* rightSwipeGestureRecognizer = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(handleSwipes:)];        leftSwipeGestureRecognizer.direction  = UISwipeGestureRecognizerDirectionLeft ;    rightSwipeGestureRecognizer.direction = UISwipeGestureRecognizerDirectionRight;        [self.view addGestureRecognizer:leftSwipeGestureRecognizer];    [self.view addGestureRecognizer:rightSwipeGestureRecognizer];}- (void)handleSwipes:(UISwipeGestureRecognizer *)sender{    if (sender.direction == UISwipeGestureRecognizerDirectionLeft) {    }        if (sender.direction == UISwipeGestureRecognizerDirectionRight) {        [[self navigationController] popViewControllerAnimated:YES];    }}