ArcGIS Engine坐標點單位轉換（由米轉化為經緯度）

　　//獲取圖層IFeatureClass

var lqpkFC = lqpkLayer.FeatureClass;

//獲取圖層坐標系統
var pSpatialRef = (lqpkFC as IGeoDataset).SpatialReference;
var pProCoordSys = pSpatialRef as IProjectedCoordinateSystem;
var pGeographCoordinateSys =pProCoordSys.GeographicCoordinateSystem;

//坐標系轉換,將投影坐標轉換為對應的地理坐標
IGeometry pGeo = (IGeometry) centerPoint;
pGeo.SpatialReference = pProCoordSys;
pGeo.Project(pGeographCoordinateSys);