说明：  通用的电子地图下载，支持多种地图的瓦片下载，如今互联网地图的地图内容分为两种，一种是栅格地图瓦片，一种是矢量地图瓦片。 栅格地图瓦片栅格地图瓦片是一种比较传统的模式，将矢量数据渲染成为256×256像素大小的图片。
(The general electronic map download, supporting tile downloads of multiple maps. Nowadays, the map content of Internet map can be divided into two parts, one is grid map tile, the other is vector map tile. Raster map tile raster map tile is a more traditional pattern, rendering vector data into 256 x 256 pixel size pictures.)