防止 MKMapView 更改选择（干净）

Question

我有一个MKPinAnnotationView 的自定义子类，它显示了一个自定义调用。我想在该注释中处理触摸事件。

我有一个可行的解决方案（如下），但感觉不对。我有一条经验法则，每当我使用 performSelector: .. withDelay: 时，我都是在与系统作斗争，而不是与它一起工作。

对于 MKMapView 的激进事件处理和注释选择处理，是否有人有一个好的、干净的解决方法？

我目前的解决方案：

（我的注释选择类中的所有代码）

我自己进行命中测试（没有这个我的手势识别器不会触发，因为地图视图会消耗事件：

- (UIView*)hitTest:(CGPoint)point withEvent:(UIEvent*)event; {
    // To enable our gesture recogniser to fire. we have to hit test and return the correct view for events inside the callout.

    UIView* hitView = nil;

    if (self.selected) {
        // check if we tpped inside the custom view
        if (CGRectContainsPoint(self.customView.frame, point))
            hitView = self.customView;
    }

    if(hitView) {
        // If we are performing a gesture recogniser (and hence want to consume the action)
        // we need to turn off selections for the annotation temporarily
        // the are re-enabled in the gesture recogniser.
        self.selectionEnabled = NO;

        // *1* The re-enable selection a moment later
        [self performSelector:@selector(enableAnnotationSelection) withObject:nil afterDelay:kAnnotationSelectionDelay];

    } else {
        // We didn't hit test so pass up the chain.
        hitView = [super hitTest:point withEvent:event];
    }

    return hitView;
}

请注意，我还关闭了选择，以便在我覆盖的 setSelected 中我可以忽略取消选择。

- (void)setSelected:(BOOL)selected animated:(BOOL)animated; {
    // If we have hit tested positive for one of our views with a gesture recogniser,  temporarily 
    // disable selections through _selectionEnabled
    if(!_selectionEnabled){
        // Note that from here one, we are out of sync with the enclosing map view
        // we're just displaying out callout even though it thinks we've been deselected
        return;
    }

    if(selected) {
        // deleted code to set up view here
        [self addSubview:_customView];

        _mainTapGestureRecogniser = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(calloutTapped:)];
        [_customView addGestureRecognizer: _mainTapGestureRecogniser];

    } else {
        self.selected = NO;
        [_customView removeFromSuperview];
    }


}

这是我不喜欢的评论 1 的行，但它在 theta 延迟火的末尾也很毛茸茸。我必须返回 superview 链才能到达 mapView，这样我才能说服它选择仍然存在。

// Locate the mapview so that we can ensure it has the correct annotation selection state after we have ignored selections.
- (void)enableAnnotationSelection {
    // This reenables the seelction state and resets the parent map view's idea of the
    // correct selection i.e. us.
    MKMapView* map = [self findMapView];
    [map selectAnnotation:self.annotation animated:NO];
    _selectionEnabled = YES;

}

与

-(MKMapView*)findMapView; {
    UIView* view = [self superview];
    while(!_mapView) {
        if([view isKindOfClass:[MKMapView class]]) {
            _mapView = (MKMapView*)view;
        } else if ([view isKindOfClass:[UIWindow class]]){
            return nil;
        } else{
            view = [view superview];
            if(!view)
                return nil;
        }
    }

    return _mapView;
}

这一切似乎都可以在没有和缺点的情况下工作（就像我从其他解决方案中看到的闪烁一样。它相对简单，但感觉不对。

谁有更好的解决方案？

Answer 1

我认为您无需担心地图视图的选择跟踪。如果我正确地解释了您想要的内容，您应该能够通过将hitTest:withEvent: 覆盖并将canShowCallout 设置为NO 来完成它。在setSelected: 中相应地执行您的标注出现/消失动画。您还应该覆盖 setHighlighted: 并调整自定义标注的显示（如果可见）。