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iOS中手势的种类很丰富,同时各类手势之间是互斥的,同类手势之间是可以并存,并分别执行的。我们以给一个UIImageView实例添加手势为例,简要的介绍下。
// 初始化一个UIimageView UIImageView *imageView = [[UIImageView alloc]initWithFrame:CGRectMake(100, 100, 300, 300)]; imageView.image = [UIImage imageNamed:@"12.jpg"];// UIImageView的用户交互是默认关闭的,要想使他可以处理触摸事件,我们得手动打开它 [imageView setUserInteractionEnabled:YES]; [self.window addSubview:imageView];
//初始化一个视图(响应者)来承载手势 /*UIView *gestureView = [[UIView alloc] initWithFrame:CGRectMake(100, 100, 100, 100)]; //当前视图放置到屏幕中央 gestureView.center = self.window.center; gestureView.backgroundColor = [UIColor yellowColor]; [self.window addSubview:gestureView];
//创建轻拍手势 UITapGestureRecognizer *tapGR = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tapAction:)];
设置触控对象,和轻拍的次数
//设置触控对象的个数(几个手指) [tapGR setNumberOfTouchesRequired:1]; //设置轻拍次数 [tapGR setNumberOfTapsRequired:2];
//给创建好的视图添加手势 // [gestureView addGestureRecognizer:tapGR];
//轻拍手势的回调方法- (void)tapAction:(UITapGestureRecognizer*)sender{ //可以根据手势得到它当前所作用的视图 UIImageView *imageView = (UIImageView*)sender.view; //得到textfield viewWithTag此方法的返回值为UIView类型,但是UITextField为UIView的子类,父类对象不能直接指向子类对象,所以需要强制转换// UITextField *textField = (UITextField*)[self.window viewWithTag:1000];// //回收键盘,取消第一响应者// [textField resignFirstResponder]; NSLog(@"我轻拍了gestureView");}
//创建捏合手势 UIPinchGestureRecognizer* pinchGR = [[UIPinchGestureRecognizer alloc] initWithTarget:self action:@selector(pinchAction:)]; pinchGR.delegate = self; // 可以在同一个视图上实现多个手势
//捏合手势的回调方法- (void)pinchAction:(UIPinchGestureRecognizer*)sender{ //通过捏合手势的到缩放比率 float scale = sender.scale; //得到该手势所作用的视图 UIView *view = sender.view; //2D仿射变换函数中的缩放函数来实现视图的放大缩小 //是在原有基础上来改变当前的视图 //函数的第一个参数:现有的视图的transform值 //第二个参数:x轴上的缩放比率 //第三个参数:y轴上的缩放比率 //是在视图最初的transform状态上改变,不管执行多少次,都是以该视图最初的transform状态为基础来改变 view.transform = CGAffineTransformMakeScale(2, 2);// view.transform = CGAffineTransformScale(view.transform, scale, scale); //每次捏合动作完毕之后,让此捏合值复原,使得它每次都是从100%开始缩放 sender.scale = 1;}
//旋转手势 UIRotationGestureRecognizer* rotaGR = [[UIRotationGestureRecognizer alloc] initWithTarget:self action:@selector(rotaAction:)]; rotaGR.delegate = self;
//旋转手势回调方法- (void)rotaAction:(UIRotationGestureRecognizer*)sender{ //通过手势的到旋转角度 float rota = sender.rotation; //得到该手势作用的视图 UIView *view = sender.view; //通过2D仿射变换函数中的旋转函数来使得当前视图旋转。 view.transform = CGAffineTransformRotate(view.transform, rota); //复原// sender.rotation = 0; sender.rotation = 0;}
//平移手势 UIPanGestureRecognizer *panGP = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(panAction:)];
//平移手势的回调方法- (void)panAction:(UIPanGestureRecognizer*)sender{ //得到当前手势所在视图 UIView *view = sender.view; //得到我们在视图上移动的偏移量 CGPoint currentPoint = [sender translationInView:view.superview]; //通过2D仿射变换函数中与位移有关的函数实现视图位置变化 view.transform = CGAffineTransformTranslate(view.transform, currentPoint.x, currentPoint.y); //复原 // 每次都是从00点开始 [sender setTranslation:CGPointZero inView:view.superview];}
//边缘轻扫手势 UIScreenEdgePanGestureRecognizer *edgePanGR = [[UIScreenEdgePanGestureRecognizer alloc] initWithTarget:self action:@selector(edgePanAction:)]; edgePanGR.edges = UIRectEdgeAll;
//边缘轻扫手势回调方法- (void)edgePanAction:(UIScreenEdgePanGestureRecognizer*)sender{ NSLog(@"我成功的触发了屏幕边缘手势");}
// ⑥长按手势 UILongPressGestureRecognizer *longPressPR = [[UILongPressGestureRecognizer alloc]initWithTarget:self action:@selector(longPressAction:)]; longPressPR.minimumPressDuration = 1;
// ⑥长按手势的回调方法- (void)longPressAction:(UILongPressGestureRecognizer *)sender{ if (sender.state == UIGestureRecognizerStateEnded) { UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:@"看你麻痹" message:@"不服你咬死我" delegate:self cancelButtonTitle:@"取消" otherButtonTitles:@"确定", nil]; [alertView show]; }}
// ⑦轻扫手势 UISwipeGestureRecognizer *swipeGR = [[UISwipeGestureRecognizer alloc]initWithTarget:self action:@selector(swipeAction:)];
// ⑦轻扫手势的回调方法- (void)swipeAction:(UISwipeGestureRecognizer *)sender{ if (sender.state == UIGestureRecognizerStateEnded) { UIActionSheet *actionSheet = [[UIActionSheet alloc]initWithTitle:@"槽尼玛" delegate:self cancelButtonTitle:@"纸张" destructiveButtonTitle:@"哈哈哈" otherButtonTitles:@"切毛毛", nil]; [actionSheet showInView:self.window]; }}
// 3.给图片添加手势 一个视图可以添加多种手势,但是一个手势,只能添加到一个视图上 [imageView addGestureRecognizer:tapGR]; [imageView addGestureRecognizer:pinchGR]; [imageView addGestureRecognizer:rotaGR]; [imageView addGestureRecognizer:panGR]; [imageView addGestureRecognizer:edgePanGR]; [imageView addGestureRecognizer:longPressPR]; [imageView addGestureRecognizer:swipeGR];
当一个视图上想要添加多种手势的时候就要用到手势的代理(重点)
// 使得多个手势可以同时响应- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer{ // 返回值为YES的时候,当执行一个手势的操作的时候,也可以执行其他手势的操作 return YES;}
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