如何从通过 MKAnnotationView 添加的按钮获取点击事件

Question

任何人都知道是否有办法从添加到MKAnnotationView 的button 获取点击事件，这个button 用作标签只是为了显示map 上每个引脚的名称，现在我单击pin 时成功显示自定义view（包含图像、文本...），因此单击按钮（标签）时我需要做同样的事情。

感谢您提供的任何建议。

button 在MKAnnotationView 中的代码：

UIButton * pinButton = [[UIButton alloc] initWithFrame:CGRectMake(0, 0, 140, 28)];
[pinButton.titleLabel setTextColor:[UIColor colorWithRed:255/255.0 green:255/255.0 blue:255/255.0 alpha:1]]; 
[pinButton setCenter:CGPointMake(pinAnnotationView.center.x + 70, pinAnnotationView.center.y + 10)]; 
[pinButton addTarget:self action:@selector(pinLabelClicked) forControlEvents:UIControlEventTouchUpInside]; 
[pinAnnotationView addSubView:pinButton]; 
[pinButton setUserInteractionEnabled:YES];

Answer 1

标准的 UI 方法是使用标注视图并添加一个附件按钮，如 progrmr 所示。

但是，如果您必须将按钮直接添加到MKAnnotationView，您的方法的问题是MKPinAnnotationView 的默认框架（不能轻易更改）小于您的按钮添加因此大多数按钮将不会响应触摸，即使您切换到使用 MKAnnotationView 并增加帧大小，MKMapView 也会阻止按钮获得任何触摸。

您需要做的是向按钮添加UITapGestureRecognizer（使用手势处理程序的操作方法而不是按钮上的addTarget）并将按钮添加到具有适当帧大小的普通MKAnnotationView MKPinAnnotationView.

例子：

- (MKAnnotationView *)mapView:(MKMapView *)mapView 
        viewForAnnotation:(id<MKAnnotation>)annotation
{
    MKAnnotationView *annView = (MKAnnotationView *)[mapView 
            dequeueReusableAnnotationViewWithIdentifier: @"pin"];
    if (annView == nil)
    {
        annView = [[[MKAnnotationView alloc] initWithAnnotation:annotation 
                      reuseIdentifier:@"pin"] autorelease];

        annView.frame = CGRectMake(0, 0, 200, 50);

        UIButton *pinButton = [UIButton buttonWithType:UIButtonTypeRoundedRect];
        pinButton.frame = CGRectMake(0, 0, 140, 28);
        pinButton.tag = 10;

        UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] 
            initWithTarget:self action:@selector(handlePinButtonTap:)];
        tap.numberOfTapsRequired = 1;
        [pinButton addGestureRecognizer:tap];
        [tap release];

        [annView addSubview:pinButton]; 
    }

    annView.annotation = annotation;

    UIButton *pb = (UIButton *)[annView viewWithTag:10];
    [pb setTitle:annotation.title forState:UIControlStateNormal];

    return annView;
}

- (void) handlePinButtonTap:(UITapGestureRecognizer *)gestureRecognizer 
{
    UIButton *btn = (UIButton *) gestureRecognizer.view;
    MKAnnotationView *av = (MKAnnotationView *)[btn superview];
    id<MKAnnotation> ann = av.annotation;
    NSLog(@"handlePinButtonTap: ann.title=%@", ann.title);
}

请注意，这将阻止地图视图的 didSelectAnnotationView 委托方法触发。如果您需要触发该方法（在 addition 到按钮的手势处理程序方法中），请添加以下内容：

//in the view controller's interface:
@interface YourVC : UIViewController <UIGestureRecognizerDelegate>

//where the UITapGestureRecognizer is created:
tap.delegate = self;

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

Answer 2

我使用此代码（为清楚起见而减少了）向标注视图（在我的应用程序中）添加了一个按钮：

-(MKAnnotationView *)mapView:(MKMapView *)map 
        viewForAnnotation:(StationItem*)annotation
{
    static NSString *AnnotationViewID = @"stationViewId";

    if ([annotation isKindOfClass:[MKUserLocation class]]) {
        return nil;  // use default user location view
    }

    MKPinAnnotationView *annotationView = 
        (MKPinAnnotationView*) [mapView dequeueReusableAnnotationViewWithIdentifier:AnnotationViewID];

    if (annotationView == nil) {
        // if an existing pin view was not available, create one
        annotationView = [[[MKPinAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:AnnotationViewID] autorelease];

        // add rightAccessoryView
        UIButton* aButton = [UIButton buttonWithFrame:CGRectMake(0, 0, 75, 30)];
        [aButton setTitle:@"Directions" forState:UIControlStateNormal];
        annotationView.rightCalloutAccessoryView = aButton;
    }

    annotationView.annotation = annotation;
    annotationView.canShowCallout = YES;
    annotationView.animatesDrop   = NO;

    return annotationView;
}

完成此操作后，您需要实现 MKMapViewDelegate 以在点击按钮时处理对委托的回调：

- (void)mapView:(MKMapView *)mapView annotationView:(MKAnnotationView *)view calloutAccessoryControlTapped:(UIControl *)control

Answer 3

尝试将触摸传递给子视图：

- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
 [pinButton touchesEnded:touches withEvent:event];
}

如果你的 buttonView 在前面，我很惊讶你有问题？尝试确保它是： [self bringSubviewToFront:pinButton];