解决方法
快速浏览Apple关于MKMapView的文档：
rotateEnabled A Boolean value indicating whether the map camera’s
heading information is used.@property(nonatomic,getter=isRotateEnabled) BOOL rotateEnabled
Discussion When this property is set to YES and a valid camera is
associated with the map,the camera’s heading angle is used to rotate
the plane of the map around its center point. When this property is
set to NO,the camera’s heading angle is ignored and the map is always
oriented so that true north is situated at the top of the map view.
因此,您可以尝试将mapview rotateEnabled属性设置为’NO’.
