在自定义 MKAnnotationView 中使用 UILongPressGestureRecognizer 时遇到问题 [英] Trouble using UILongPressGestureRecognizer in custom MKAnnotationView

问题描述

在 MKAnnotationView 的自定义子类中使用 UILongPressGestureRecognizer 时遇到问题.回调只会间歇性地触发.如果我使 minimumPressDuration 更短，它会更频繁地触发.当 minimumPressDuration 值为 0.1 时，它每次都会触发.值为 0.4 时，无论我将手指放在上面多久，它都不会触发.在 0.2 时命中或未命中.

Having trouble with a UILongPressGestureRecognizer in a custom subclass of MKAnnotationView. The callback is fired only intermittently. If I make the minimumPressDuration shorter, it fires more frequently. With a minimumPressDuration value of 0.1, it fires every time. With a value of 0.4, it never fires at all, no matter how long I leave my finger on it. At 0.2 it is hit or miss.

如果我使用 Tap 手势(如下所示)，它工作正常.我在其他视图上使用 LongPress 手势，它们工作正常.我只是在 MKAnnotationView 上遇到了这个问题，所以我想知道 AnnotationViews 上的其他一些内部事件回调是否有干扰(标注等).

If I use a Tap gesture (as below), it works fine. I'm using LongPress gestures on other views and they work fine. It's just on the MKAnnotationView that I have this problem, so I'm wondering if some of the other internal event callbacks on AnnotationViews are interfering (callout, etc).

我在 iOS4(sim 和手机)和 3.2(sim，没有设备)上看到这个问题.

I see this problem on iOS4 (sim and phone) and 3.2 (sim, don't have a device).

这是我创建手势识别器的方法:

Here is how I'm creating the gesture recognizer:

#define USE_LONG_PRESS 1
#define USE_TAP 0
#if USE_LONG_PRESS
    UILongPressGestureRecognizer *longPressGR = 
    [[UILongPressGestureRecognizer alloc] initWithTarget:self 
                                                action:@selector(handleLongPress:)];
    longPressGR.minimumPressDuration = 0.2;
    [self addGestureRecognizer:longPressGR];
    [longPressGR release];
#endif
#if USE_TAP
    UITapGestureRecognizer *tapGR = 
    [[UITapGestureRecognizer alloc] initWithTarget:self 
                                                action:@selector(handleTap:)];
    [self addGestureRecognizer:tapGR];
    [tapGR release];
#endif

并且回调方法在这个类中定义如下:

And the callback methods are defined in this class as follows:

- (void)handleLongPress:(UIGestureRecognizer *)gestureRecognizer {
    NSLog(@"LONG PRESS");
}

- (void)handleTap:(UIGestureRecognizer *)gestureRecognizer {
    NSLog(@"TAP");
}

任何 iPhone 专家都知道为什么会发生这种情况?

Any iPhone gurus have any idea why this might be happening?

推荐答案

据我所知，3.2 和 iOS 4 中的标记已经附加了一个长按手势来处理标记拖动.难道这会干扰您的长按手势识别器?也许这就是为什么较短的持续时间起作用的原因；它在内置的长按识别器可以之前捕获手势.

As far as I know the markers in 3.2 and iOS 4 already have a long press gesture attached to them to handle marker dragging. Could it be that that's interfering with your long press gesture recognizer? Maybe that's why a shorter duration works; it catches the gesture before the built in long press recognizer can.

• 这只是猜测*

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