iphone自定义手势
时间: 2023-09-19 15:13:29 浏览: 68
苹果提供了UIGestureRecognizer类,可以用来实现自定义手势。下面是一个简单的例子,实现在屏幕上绘制一个“V”形手势来触发事件:
1. 首先在视图控制器中创建一个手势识别器对象:
```
@property (nonatomic, strong) UIGestureRecognizer *gestureRecognizer;
```
2. 在viewDidLoad方法中,创建手势识别器并将其添加到视图上:
```
self.gestureRecognizer = [[UIGestureRecognizer alloc] initWithTarget:self action:@selector(handleGesture:)];
[self.view addGestureRecognizer:self.gestureRecognizer];
```
3. 实现手势处理方法,当手势被识别时,执行自定义的事件:
```
- (void)handleGesture:(UIGestureRecognizer *)gestureRecognizer {
if (gestureRecognizer.state == UIGestureRecognizerStateEnded) {
NSArray *points = [gestureRecognizer valueForKey:@"touches"];
CGPoint startPoint = [[points firstObject] locationInView:self.view];
CGPoint endPoint = [[points lastObject] locationInView:self.view];
// 计算手势的方向
CGFloat dx = endPoint.x - startPoint.x;
CGFloat dy = endPoint.y - startPoint.y;
if (dx > 0 && dy < 0 && fabs(dx) > fabs(dy)) {
// 手势为向右上方,执行自定义事件
[self doSomething];
}
}
}
```
在上面的代码中,我们使用了touches属性获取手势的起点和终点,然后计算手势的方向,最后根据手势的方向执行自定义事件。
注意:在创建手势识别器时,需要指定手势的类型,例如:
```
UISwipeGestureRecognizer *swipeRecognizer = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(handleSwipe:)];
swipeRecognizer.direction = UISwipeGestureRecognizerDirectionRight;
[self.view addGestureRecognizer:swipeRecognizer];
```
上面的代码创建了一个向右滑动的手势识别器,并将其添加到视图上。当手势被识别时,会执行handleSwipe:方法。