c++进行经纬度坐标与平面坐标转换（转）

原文地址：http://www.cnblogs.com/ayanmw/archive/2012/08/19.html
IPoint* projToGeo(IPoint* point/*需要更改坐标系的点*/,long fromProjType=3857 ,long toGeoType=4326)
    {
        long geoType = toGeoType;//4326;
        IPoint* points = point;
        ISpatialReference* spatialRf;
        ISpatialReference* spatialRf1;
        IGeographicCoordinateSystem* geograpicsys;
        IProjectedCoordinateSystem*projCoordSystem;
        ISpatialReferenceFactoryPtr originalSpecialReference;
        ISpatialReferenceFactoryPtr newReferenceSystem;
    
        HRESULT hr = originalSpecialReference.CreateInstance(CLSID_SpatialReferenceEnvironment);
        HRESULT hr1 = originalSpecialReference->CreateProjectedCoordinateSystem(fromProjType,&projCoordSystem);
        spatialRf = (ISpatialReference*)projCoordSystem;
        HRESULT hr2 = points->putref_SpatialReference(spatialRf);


        newReferenceSystem.CreateInstance(CLSID_SpatialReferenceEnvironment);
        newReferenceSystem->CreateGeographicCoordinateSystem(geoType,&geograpicsys);
        spatialRf1 = (ISpatialReference*)geograpicsys;
        //points->putref_SpatialReference(spatialRf1);//这句不能要是设置原始 空间参考的。

        points->Project(spatialRf1);
        ////测试输出而已////////////////////////
        //double x,y;
        //points->get_X(&x);
        //points->get_Y(&y);
        //printf("x=%lf,y=%lf\n",x,y);
        ///////////////////////////////////////
        return points;
    };