MKMapSnapshotter如何设置引脚图像

Question

我创建引脚图像的代码如下：

 MKMapSnapshotOptions *options = [[MKMapSnapshotOptions alloc] init];
options.region = MKCoordinateRegionMakeWithDistance(userLocation, 300, 300) ;
options.size = CGSizeMake(320,180);
options.scale = [UIScreen mainScreen].scale;

MKMapSnapshotter *snapShotter = [[MKMapSnapshotter alloc] initWithOptions:options];

[snapShotter startWithCompletionHandler:^(MKMapSnapshot *snapshot, NSError *error) {
    //
    if (error) {
        NSLog(@"err = %@",[error description]);
    }

    UIImage *img = snapshot.image;

    MKAnnotationView *pin = [[MKPinAnnotationView alloc] initWithAnnotation:nil reuseIdentifier:nil];
    CGPoint coordinatePoint = [snapshot pointForCoordinate:userLocation];


    coordinatePoint.x += pin.centerOffset.x - (CGRectGetWidth(pin.bounds) / 2.0);
    coordinatePoint.y += pin.centerOffset.y - (CGRectGetHeight(pin.bounds) / 2.0);

    UIGraphicsBeginImageContextWithOptions(img.size, YES, img.scale);
    {
        [img drawAtPoint:CGPointZero];
        [pin.image drawAtPoint:coordinatePoint];
        _imgViewMapThubbnail.image = UIGraphicsGetImageFromCurrentImageContext();
    }
    UIGraphicsEndImageContext();
    _imgViewMapThubbnail.layer.cornerRadius = 10 ;
    _imgViewMapThubbnail.layer.masksToBounds = true ;

}];

这个代码是正常的红色引脚，位置几乎正确。我想要我的自定义pin，所以我添加了如下代码

pin.image = [UIImage imageNamed:@"MY_IMAGE_NAME"];

引脚图像已更改，并且工作正常。然而，我的位置有一些不同。我不知道，如何调整我的代码或引脚图像大小，以设置到正确的位置？

Answer 1

考虑到这是一个老问题，对于任何来这里定制引脚图像的人来说，这里有一个来自上面示例的修订代码，它可以将引脚渲染到正确的位置。

CGPoint coordinatePoint = [snapshot pointForCoordinate:newCenter];
    UIImage *pin = [UIImage imageNamed:@"pin"];
    CGPoint centerOffset = CGPointMake(0, -pin.size.height / 2);
    coordinatePoint.x += centerOffset.x - (pin.size.width / 2.0);
    coordinatePoint.y += centerOffset.y - (pin.size.height / 2.0);

    UIGraphicsBeginImageContextWithOptions(img.size, YES, img.scale);
    {
        [img drawAtPoint:CGPointZero];
        [pin drawAtPoint:coordinatePoint];
        _imgViewMapThubbnail.image = UIGraphicsGetImageFromCurrentImageContext();
    }
    UIGraphicsEndImageContext();