Delphi地图定位功能的实例，一个模糊的实现，可能会有问题，有经验的可修复一下代码，可让新手了解一下定位的基本原理。 -Delphi map positioning instance, a vague realization, there may be problems experienced repairable at the code that allows the novice to understand what the basic principles of positionin