Google Maps SDK 中的自定义注释视图

我创建了一个基于地图的 iOS 应用程序，其中我想使用 iOS 版 Google Maps SDK 而不是 Mapkit，我找到了文档，但没有找到与自定义注释视图相关的方法，任何人都可以为我提供解决方案创建自定义注释视图（信息窗口）以及如何为其添加内容（标题、片段）。

我不知道你们怎么想，但我发现 Google 渲染的 UIView 信息窗口有点限制。使用SMCallout视图 https://github.com/nfarina/calloutview and Ryan Maxwell 的示例项目 https://github.com/ryanmaxwell/GoogleMapsCalloutView，可以呈现更多交互式视图。

截至 2014 年 6 月 10 日，这适用于 Google Maps SDK v1.8.1。

首先，做一些设置：

#import <SMCalloutView/SMCalloutView.h>

static const CGFloat CalloutYOffset = 10.0f;

@interface ViewController ()
@property (strong, nonatomic) SMCalloutView *calloutView;
@property (strong, nonatomic) UIView *emptyCalloutView;
@end

初始化SMCalloutView，向其添加一个按钮，然后创建一个空的UIView:

- (void)viewDidLoad
{
    /* all your other view init, settings, etc... */

    self.calloutView = [[SMCalloutView alloc] init];
    self.calloutView.hidden = YES;

    UIButton *button = [UIButton buttonWithType:UIButtonTypeDetailDisclosure];
    [button addTarget:self
               action:@selector(calloutAccessoryButtonTapped:)
     forControlEvents:UIControlEventTouchUpInside];
    self.calloutView.rightAccessoryView = button;

    self.emptyCalloutView = [[UIView alloc] initWithFrame:CGRectZero];
}

我们必须画出那个空的UIView以满足Maps SDK的要求，但我们将显示的视图是SMCalloutView。我还为标注视图设置了可重用的垂直偏移。

添加委托方法来处理信息窗口调用：

#pragma mark - GMSMapViewDelegate

- (UIView *)mapView:(GMSMapView *)mapView markerInfoWindow:(GMSMarker *)marker {
    CLLocationCoordinate2D anchor = marker.position;

    CGPoint point = [mapView.projection pointForCoordinate:anchor];

    self.calloutView.title = marker.title;

    self.calloutView.calloutOffset = CGPointMake(0, -CalloutYOffset);

    self.calloutView.hidden = NO;

    CGRect calloutRect = CGRectZero;
    calloutRect.origin = point;
    calloutRect.size = CGSizeZero;

    [self.calloutView presentCalloutFromRect:calloutRect
                                      inView:mapView
                           constrainedToView:mapView
                                    animated:YES];

    return self.emptyCalloutView;
}

- (void)mapView:(GMSMapView *)pMapView didChangeCameraPosition:(GMSCameraPosition *)position {
    /* move callout with map drag */
    if (pMapView.selectedMarker != nil && !self.calloutView.hidden) {
        CLLocationCoordinate2D anchor = [pMapView.selectedMarker position];

        CGPoint arrowPt = self.calloutView.backgroundView.arrowPoint;

        CGPoint pt = [pMapView.projection pointForCoordinate:anchor];
        pt.x -= arrowPt.x;
        pt.y -= arrowPt.y + CalloutYOffset;

        self.calloutView.frame = (CGRect) {.origin = pt, .size = self.calloutView.frame.size };
    } else {
        self.calloutView.hidden = YES;
    }
}

- (void)mapView:(GMSMapView *)mapView didTapAtCoordinate:(CLLocationCoordinate2D)coordinate {
    self.calloutView.hidden = YES;
}

- (BOOL)mapView:(GMSMapView *)mapView didTapMarker:(GMSMarker *)marker {
    /* don't move map camera to center marker on tap */
    mapView.selectedMarker = marker;
    return YES;
}

处理标注按钮上的触摸，此处使用带有标记标题和片段的警报视图：

- (void)calloutAccessoryButtonTapped:(id)sender {
    if (mapView_.selectedMarker) {
        GMSMarker *marker = mapView_.selectedMarker;
        //NSDictionary *userData = marker.userData;

        UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:marker.title
                                                            message:marker.snippet
                                                           delegate:nil
                                                  cancelButtonTitle:@"OK"
                                                  otherButtonTitles:nil];
        [alertView show];
    }
}

显然，请确保您的 ViewController(.h) 监听 GMSMapViewDelegate：

@interface ViewController : UIViewController <GMSMapViewDelegate>

这基本上应该有效。完整的xcode项目请参见前述example https://github.com/ryanmaxwell/GoogleMapsCalloutView来自瑞恩·麦克斯韦。