标签：body das image openlayer UI play content nbu 代码
参照别人的添加marker的demo来改造时，发现无论怎样更改经纬度，都是停留在同一个位置。过了一两天突然想起可能是坐标参考的问题，尝试搜了一下，果然是这个问题。问题是这样子的：
WMTS中地图的坐标参考系是102100（具体是哪个不清楚），如下图所示：
而我在初始化地图时设置的参数如下图所示：projection属性设置的是‘EPSG：102100’，displayProjection属性设置的是‘EPSG：4326’，也即经纬度显示。
{String} Set in the map options to specify the default projection for layers added to this map. When using a projection other than EPSG:4326 (CRS:84, Geographic) or EPSG:3857 (EPSG:900913, Web Mercator), also set maxExtent, maxResolution or resolutions. Default is “EPSG:4326”. Note that the projection of the map is usually determined by that of the current baseLayer (see baseLayer and getProjectionObject).
{OpenLayers.Projection} Requires proj4js support for projections other than EPSG:4326 or EPSG:900913/EPSG:3857. Projection used by several controls to display data to user. If this property is set, it will be set on any control which has a null displayProjection property at the time the control is added to the map.
因此如果要利用经纬度进行定位标记的话，需要进行坐标转换，即EPSG：4326—>EPSG:102100，主要用到OpenLayers.LonLat的transform函数，代码如下：
标签：body das image openlayer UI play content nbu 代码
原文地址：http://www.cnblogs.com/love540376/p/6775168.html
