手势检测

- (void)viewDidLoad{    [super viewDidLoad];// Do any additional setup after loading the view.    UISwipeGestureRecognizer *recognizer;    recognizer = [[UISwipeGestureRecognizer alloc]initWithTarget:self action:@selector(handleSwipeFrom:)];    [recognizer setDirection:(UISwipeGestureRecognizerDirectionDown)];    [[self view] addGestureRecognizer:recognizer];    [recognizer release];}-(void)handleSwipeFrom:(UISwipeGestureRecognizer *)recognizer{        if(recognizer.direction==UISwipeGestureRecognizerDirectionDown)    {        [self dismissViewControllerAnimated:YES completion:nil];    }}