如何将CGRect转换为MapRect

Question

我创建了一个方法，如下所示将CGRect转换为MapRect

- (MKMapRect)mapRectForRect:(CGRect)rect
{
    CLLocationCoordinate2D topleft = [mapView convertPoint:CGPointMake(rect.origin.x, rect.origin.y) toCoordinateFromView:canvasView];
    CLLocationCoordinate2D bottomeright = [mapView convertPoint:CGPointMake(CGRectGetMaxX(rect), CGRectGetMaxY(rect)) toCoordinateFromView:canvasView];
    MKMapPoint topleftpoint = MKMapPointForCoordinate(topleft);
    MKMapPoint bottomrightpoint = MKMapPointForCoordinate(bottomeright);
    return MKMapRectMake(topleftpoint.x, topleftpoint.y, bottomrightpoint.x - topleftpoint.x, bottomrightpoint.y - topleftpoint.y);
}

我做了一个小测试。

    UIImageView *imageView = [[UIImageView alloc] initWithImage:[[UIImage imageNamed:@"heart.png"] imageByScalingProportionallyToSize:CGSizeMake(100, 100)]];
    imageView.frame = CGRectMake(0, 0, 100, 100);
    imageView.center = [mapView convertCoordinate:mapView.centerCoordinate toPointToView:canvasView];
    [canvasView addSubview:imageView];
    CGRect rect = imageView.frame;
    for (int i = 0; i < 5; i ++)
    {
        NSLog(@"%f, %f, %f, %f", rect.origin.x, rect.origin.y, rect.size.width, rect.size.height);
        maprect = [self mapRectForRect:rect];
        NSLog(@"%f, %f, %f, %f", maprect.origin.x, maprect.origin.y, maprect.size.width, maprect.size.height);
        region = MKCoordinateRegionForMapRect(maprect);
        rect = [mapView convertRegion:region toRectToView:canvasView];
    }

它在iOS 5:上运行得很好

110.00000、180.0000000、100.000000、100.000000

78118912.00000094811514.400625252428800.00000052428799.999997

110.00000、180.0000000、100.000000、100.000000

78118912.00000094811514.400625252428800.00000052428799.999997

110.00000、180.0000000、100.000000、100.000000

78118912.00000094811514.400625252428800.00000052428799.999997

110.00000、180.0000000、100.000000、100.000000

78118912.00000094811514.400625252428800.00000052428799.999997

110.00000、180.0000000、100.000000、100.000000

78118912.00000094811514.400625252428800.00000052428799.999997

但是，iOS 4.3上的结果有点奇怪。

110.00000、180.0000000、100.000000、100.000000

78118912.00000094811514.400625252428800.00000052428799.999997

110.000000174.265396100.000000101.746048

78118912.00000091803986.4060252428800.00000053344231.999997

110.000000166.962997100.000000104.330460

78118912.000000、87976370.406253、52428800.000000、54699207.999997

110.000000157.400009，100.000000108.272507

78118912.00000082962610.40625352428800.00000056765975.999997

110.000000144.2974701100.000000114.581375

78118912.0000007609310626452428800.00000060073639.999996

Answer 1

类似这样的东西（Swift代码）似乎工作得很好。在这种情况下，mapView是GMSMapView!类型，因此mapView.frame是CGRect类型。

let mkMapSize = MKMapSize(width: Double(self.mapView.frame.width), height: Double(self.mapView.frame.height))
let mkMapPoint = MKMapPoint(x: Double(self.mapView.frame.origin.x), y: Double(self.mapView.frame.origin.y))
let mkMapRect = MKMapRect(origin: mkMapPoint, size: mkMapSize)