学习iOS开发的第19天

学了一下手势识别器的运用。下面简单地演示一下。

手势包括轻击、捏合、平移、轻扫、旋转、长按等。它们分别由相应类来实现。依次为UITapGestureRecognizer、UIPinchGestureRecognizer、UIPanGestureRecognizer、UISwipeGestureRecognizer、UIRotationGestureRecognizer、UILongPressGestureRecognizer。它们都继承于UIGestureRecognizer类。创建这些类的实例来获取响应的手势事件并会绑定制定的方法，手势会触发相应的方法。创建好手势识别器后，可以将手势识别器添加到view上面。

新建一个项目，然后创建一个继承于UIViewController的视图控制器，在里面分别创建那几个手势识别器。手势识别器也有很多属性可以设置，有兴趣者可以深入研究下。

    //轻击识别器    UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tap)];    [self.view addGestureRecognizer:tap];        //捏合    UIPinchGestureRecognizer *pinch = [[UIPinchGestureRecognizer alloc] initWithTarget:self action:@selector(pinch)];    [self.view addGestureRecognizer:pinch];    //平移    UIPanGestureRecognizer *pan = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(pan)];    [self.view addGestureRecognizer:pan];    //轻扫    UISwipeGestureRecognizer *swipe = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(swipe)];    //设置方向    swipe.direction = UISwipeGestureRecognizerDirectionDown;    [self.view addGestureRecognizer:swipe];    //旋转    UIRotationGestureRecognizer *rotation = [[UIRotationGestureRecognizer alloc] initWithTarget:self action:@selector(rotation)];    [self.view addGestureRecognizer:rotation];    //长按    UILongPressGestureRecognizer *longPress = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(longPress)];    //设置长按最小时间    longPress.minimumPressDuration = 1;    [self.view addGestureRecognizer:longPress];

下面是各个手势所触发的方法。

-(void)tap{    NSLog(@"轻击");}-(void)pinch{    NSLog(@"捏合");}-(void)pan{    NSLog(@"平移");}-(void)swipe{    NSLog(@"轻扫");}-(void)rotation{    NSLog(@"旋转");}-(void)longPress{    NSLog(@"长按");}

最后在应用程序的代理类里创建视图控制器。

    TouchViewController *controller = [[TouchViewController alloc] init];    self.window.rootViewController = controller;

运行程序，在屏幕上做出各种手势，会输出相应手势的名称。