鹰眼图的主要功能是在主图发生变化时，在鹰眼图上用变化的矩形框来显示当前主图显示的边界。这里主要利用MapX 控件内置的消息MAPX_DISPID_MAPVIEWCHANGED映射的函数来完成该功能，当主视图发生变化时，MapX 控件发出消息，调用OnMapViewChanged()函数进行相应的处理，所以主要的代码在OnMapViewChanged()函数中实现。-Eagle Eye diagram of main function is to change the main map, in Eagle Eye chart changes in the rectangular box used to display the main graph shows the current borders. Here the main use of the built-in news MapX control MAPX_DISPID_MAPVIEWCHANGED mapping function to complete the function, when the main view changes, MapX control a message, call OnMapViewChanged () function for the corresponding treatment, so the main code OnMapViewChanged () function to achieve .