objective-c iphone programming : set placemark custom name

i just want to change the placemark name. I hear开发者_开发百科d i need to create a custom class but it doesn't work.

Always tell me the coordinates are in ReadOnly? Thanks

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You need to create a class that implements the MKAnnotation protocol. Your implementation can implement the title and subtitle properties. You instantiate your annotation implementation and add it to your MKMapView via addAnnotation.