openlayers3怎么与各地图的坐标转换

this.displayProjection=new OpenLayers.Projection("EPSG:4326");
this.units="m";

//this.numZoomLevels=16;
//this.maxResolution=78271.51695;

//this.numZoomLevels=15;
//this.maxResolution=39135.758475;

this.numZoomLevels=14;
//Resolution=20037508*2/256*2^(zoom+1),zoom取值0~15
this.maxResolution= 19567.8792375;
//对应经纬度（-180，-90，180*2，