ios - 防止 MKMapView 更改选择(干净地)

Question

我有一个显示自定义标注的 MKPinAnnotationView 的自定义子类。我想处理该注释内的触摸事件。

我有一个可行的解决方案(如下)，但感觉不对。我有一个经验法则，每当我使用 performSelector: .. withDelay: 时，我都是在与系统作斗争，而不是在使用它。

对于 MKMapView 的积极事件处理和注释选择处理，有没有人有一个好的、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 HitTest (如果没有这个，我的手势识别器不会在 map View 使用事件时触发:

- (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 行，但在 theta 延迟开火结束时它也很毛茸茸。我必须沿着 super View 链返回到 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;
}

这一切似乎都没有缺点(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

我认为您不需要对 map View 的选择跟踪进行操作。如果我正确地解释了你想要的，你应该能够通过 hitTest:withEvent: 覆盖和 canShowCallout 设置为 NO。在 setSelected: 中相应地执行标注出现/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)。