ios – 使用MapKit框架在谷歌地图上绘制多边形

您无需在MapKit地图(MKMapView)上添加透明视图.您创建一个叠加对象,在本例中为MKPolygon. (在下面的示例中,变量map将是您将此代码放入的视图控制器所拥有的MKMapView实例)：

CLLocationCoordinate2D  points[4];

points[0] = CLLocationCoordinate2DMake(41.000512,-109.050116);
points[1] = CLLocationCoordinate2DMake(41.002371,-102.052066);
points[2] = CLLocationCoordinate2DMake(36.993076,-102.041981);
points[3] = CLLocationCoordinate2DMake(36.99892,-109.045267);

MKPolygon* poly = [MKPolygon polygonWithCoordinates:points count:4];
poly.title = @"Colorado";

[map addOverlay:poly];

然后,如果要自定义叠加层的外观(颜色,笔触等),可以在拥有MKMapView对象的视图控制器中实现MKMapViewDelegate协议,并提供mapView的实现：viewForOverlay：

- (MKOverlayView *)mapView:(MKMapView *)mapView viewForOverlay:(id <MKOverlay>)overlay
{
    if ([overlay isKindOfClass:[MKPolygon class]])
    {
        MKPolygonView* aView = [[[MKPolygonView alloc] initWithPolygon:(MKPolygon*)overlay] autorelease];

        aView.fillColor = [[UIColor cyanColor] colorWithAlphaComponent:0.2];
        aView.strokeColor = [[UIColor blueColor] colorWithAlphaComponent:0.7];
        aView.lineWidth = 3;

        return aView;
    }

    return nil;
}

当然,总是记得在接口构建器或代码(例如viewDidLoad)中实际将地图实例的委托分配给视图控制器(MKMapViewDelegate).