今天用地图的时候有用到pinch 捏合手势
通过捏合手势动作可以很轻松的来改变视图元素的一个比例
手势的动作状态有如下三种,一般是按照顺序来进行转换的。
1. UIGestureRecognizerStateBegan
2. UIGestureRecognizerStateChanged
3. UIGestureRecognizerStateEnded
一旦捏合手势动作产生了之后,我们就需要在捕获的事件中进行一个页面调整。其中有两个比较重要的变量 scale 和 velocity ,前者是一个比例范围,后者是一个变化速率的,也就是说每次变化的一个像素点。
由于 scale 这个属性的值是每次都在变的,所以我们需要用另外一个变量来保存当前的一个scale的值,这个变量叫做currentScale,这样我们就可以进行一个缩小,变大的视图效果了 。
代码:
#import "ViewController.h" @interface ViewController () @property(nonatomic, strong)UIPinchGestureRecognizer *pinchGestureRecognizer; @property(nonatomic, strong)UIView *myView; @property(nonatomic, unsafe_unretained)CGFloat currentScale; @end @implementation ViewController - (void)viewDidLoad { [super viewDidLoad]; CGRect labelRect = CGRectMake(0, 0, 200, 200); self.myView= [[UIView alloc] initWithFrame:self.view.frame]; self.myView.center = self.view.center; self.myView.backgroundColor = [UIColor grayColor]; //打开view的交互 self.myBlackLabel.userInteractionEnabled = YES; [self.view addSubview:self.myView]; //创建一个手势 self.pinchGestureRecognizer = [[UIPinchGestureRecognizer alloc] initWithTarget:self action:@selector(handlePinches:)]; [self.myView addGestureRecognizer:self.pinchGestureRecognizer]; } #pragma mark - 手势事件-(void)handlePinches:(UIPinchGestureRecognizer *)paramSender{ if (paramSender.state == UIGestureRecognizerStateEnded) { self.currentScale = paramSender.scale; }else if(paramSender.state == UIGestureRecognizerStateBegan && self.currentScale != 0.0f){ paramSender.scale = self.currentScale; } if (paramSender.scale !=NAN && paramSender.scale != 0.0) { paramSender.view.transform = CGAffineTransformMakeScale(paramSender.scale, paramSender.scale); } } - (void)didReceiveMemoryWarning { [super didReceiveMemoryWarning]; // Dispose of any resources that can be recreated. } @end转载于:https://www.cnblogs.com/pengjuwang/p/5378830.html
相关资源:DirectX修复工具V4.0增强版