MKAnnotation image offset with custom pin image

fredrik picture fredrik · Nov 17, 2011 · Viewed 21.8k times · Source

I have a MKAnnotation with an custom pin image. However the pin(MKAnnotationView) centers the image in relation to the specified coordinate. I want to set the point of the coordinate at the bottom center of the image, not center.

I've tried using annView.centerOffset = CGPointMake(-12, -28);. But the problem is that centerOffset isn't relevant to the maps zoom level.

One can do this both in the JS API and in Android. Is there any possibility to do this in objective-c?

..fredrik

Answer

Zoleas picture Zoleas · Nov 17, 2011

Your UIAnnotationView is always drawn at the same scale, the map's zoom level doesn't matter. That's why centerOffset isn't bound with the zoom level.

annView.centerOffset is what you need. If you see that your pin is not at the good location (for example, the bottom center move a little when you change the zoom level), it's because you didn't set the right centerOffset.

By the way, if you want to set the point of the coordinate at the bottom center of the image, the x coordinate of your centerOffset should be 0.0f, as annotationView center the image by default. So try :

annView.centerOffset = CGPointMake(0, -imageHeight / 2);