AE设置投影而非重投影
读取一个jpg格式的影像，包含jgw文件，这时设置投影。赋值操作。
1 IRasterDataset raster = rasterWsp.OpenRasterDataset(FileName);
2 //AE设置投影为WebMercator投影
3 IGeoDatasetSchemaEdit schemeEdit = raster as IGeoDatasetSchemaEdit;
4 if (schemeEdit.CanAlterSpatialReference)
5 {
6 schemeEdit.AlterSpatialReference(webMercator);
7 }
构建webMercator投影：
1 //创建WGS84辅助球Web墨卡托投影
2 public ISpatialReference CreateWebMector()
3 {
4 // 实例化SpatialReferenceEnvironment.SpatialReferenceEnvironment
5 Type factoryType = Type.GetTypeFromProgID("esriGeometry.SpatialReferenceEnvironment");
6 System.Object obj = Activator.CreateInstance(factoryType);
7 ISpatialReferenceFactory3 mSpatialReferenceFactory3 = obj as ISpatialReferenceFactory3;
8 ISpatialReference projSpatialReference = mSpatialReferenceFactory3.CreateProjectedCoordinateSystem((int)esriSRProjCS3Type.esriSRProjCS_WGS1984WebMercatorMajorAuxSphere);//基于WGS84的WebMercator
9 //esriSRProjCS2Type.esriSRProjCS_WGS1984WorldMercator);
10 //esriSRProjCS3Type.esriSRProjCS_WGS1984WebMercatorMajorAuxSphere);
11 //esriSRProjCS2Type.esriSRProjCS_WGS1984SphereWebMercator
12 return projSpatialReference;
13 }