iphone - 同时使用触摸和触摸手势识别器

Question

我在我的 UIView 上使用了两个手势识别器。一个是标准的 UITapGestureRecognizer，另一个是我写的非常简单的触摸识别器:

@implementation TouchDownGestureRecognizer

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
    if (self.state == UIGestureRecognizerStatePossible) {
        self.state = UIGestureRecognizerStateRecognized;
    }
}

- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
    self.state = UIGestureRecognizerStateFailed;
}

- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
    self.state = UIGestureRecognizerStateFailed;
}

@end

只有当我为它们分配一个包含此方法的委托(delegate)时，它们才能一起工作:

- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer {
    return YES;
}

一切正常，但当我长按该 View 时，触摸识别器会触发，而触摸识别器不会。短按一切正常，它们都会开火。

我在 UIGestureRecognizerDelegate 中实现了所有方法以返回 YES 无济于事。如果我添加日志记录以查看与委托(delegate)和我自己的识别器内部的交互，我可以看到对于短按和长按，调用序列是相同的 — 除了调用 touch up 识别器。我做错了什么？

Answer 1

为什么不直接从 UILongPressGestureRecognizer 检查 touchUp？

-(void)selectionDetected:(UILongPressGestureRecognizer*)longPress
{
    if(longPress.state==1)
    {
       //long Press is being held down
    }
    else if(longPress.state==3)
    {
        //the touch has been picked up
    }
}