ios - 无法正确获取 UISwipeGestureRecognizer 方向

Question

我正在编写代码以在 View 上上下移动我的两根手指以更改某些状态。代码如下:

UISwipeGestureRecognizer *aSwipeGesture = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(swipeGesture:)];
[aSwipeGesture setDirection:UISwipeGestureRecognizerDirectionUp | UISwipeGestureRecognizerDirectionDown];
aSwipeGesture.numberOfTouchesRequired = 2;
[self.View addGestureRecognizer:aSwipeGesture];


- (void)swipeGesture:(UISwipeGestureRecognizer *)sender {
    NSLog(@"Swipe received.");
    if (sender.direction==UISwipeGestureRecognizerDirectionUp) {
        NSLog(@"swipe up");
    } else if (sender.direction==UISwipeGestureRecognizerDirectionDown) {
        NSLog(@"swipe down");
    }
}

然而，我唯一能收到的打印日志是收到的刷卡，如下所示。我无法收到向上滑动或向下滑动的消息，我是不是错过了什么？谢谢

ViewController.m:228    Swipe received.
ViewController.m:228    Swipe received.
ViewController.m:228    Swipe received.
ViewController.m:228    Swipe received.
ViewController.m:228    Swipe received.
ViewController.m:228    Swipe received.

更新:我必须用两根手指才能完成滑动 Action 。

Answer 1

试试这个

UISwipeGestureRecognizer *aSwipeGestureUp = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(swipeGesture:)];
[aSwipeGesture setDirection:UISwipeGestureRecognizerDirectionUp];
aSwipeGestureUp.numberOfTouchesRequired = 2;
[self.View addGestureRecognizer:aSwipeGestureUp];

UISwipeGestureRecognizer *aSwipeGestureDown = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(swipeGesture:)];
[aSwipeGestureDown setDirection:UISwipeGestureRecognizerDirectionDown];
aSwipeGestureDown.numberOfTouchesRequired = 2;
[self.View addGestureRecognizer:aSwipeGestureDown];