Geodatabase - 打开栅格数据

打开栅格数据

　　和打开要素类的方式类似,打开栅格数据集需要用 IRasterWorkspace,如

 //获得栅格工作空间(普通目录).
         public ESRI.ArcGIS.DataSourcesRaster.IRasterWorkspace GetRasterWorkspace(string rasterWorkspacePath) {
             ESRI.ArcGIS.Geodatabase.IWorkspaceFactory wsf = new ESRI.ArcGIS.DataSourcesRaster.RasterWorkspaceFactoryClass();    //使用RasterWorkspaceFactoryClass.
             ESRI.ArcGIS.Geodatabase.IWorkspace ws = wsf.OpenFromFile(rasterWorkspacePath, );
             ESRI.ArcGIS.DataSourcesRaster.IRasterWorkspace rws = (ESRI.ArcGIS.DataSourcesRaster.IRasterWorkspace)ws;
             return rws;
         }

         /// <summary>
         /// 打开栅格数据集(普通目录).
         /// </summary>
         /// <param name="foldName">目录名称(普通目录),如,foldName="G:\doc\gis\1.400\data\raster".</param>
         /// <param name="fileName">栅格数据集的名称,如fileName="srtm_58_09.tif"</param>
         /// <returns></returns>
         public ESRI.ArcGIS.Geodatabase.IRasterDataset OpenRasterDataset(string foldName, string fileName) {
             ESRI.ArcGIS.DataSourcesRaster.IRasterWorkspace rws = GetRasterWorkspace(foldName);
             return rws.OpenRasterDataset(fileName);
         }

         //获得栅格工作空间(数据库中).
         //如rasterWorkspaceExPath="G:\doc\gis\1.400\data\pdb.mdb"
         public ESRI.ArcGIS.Geodatabase.IRasterWorkspaceEx GetRasterWorkspaceEx(string rasterWorkspaceExPath) {
             ESRI.ArcGIS.Geodatabase.IWorkspaceFactory wsf = new ESRI.ArcGIS.DataSourcesGDB.AccessWorkspaceFactoryClass();   //使用专门数据库.
             ESRI.ArcGIS.Geodatabase.IWorkspace ws = wsf.OpenFromFile(rasterWorkspaceExPath, );
             ESRI.ArcGIS.Geodatabase.IRasterWorkspaceEx rwsEx = (ESRI.ArcGIS.Geodatabase.IRasterWorkspaceEx)ws;
             return rwsEx;
         }

         /// <summary>
         /// 打开栅格数据集(数据库中)
         /// </summary>
         /// <param name="rasterWorkspaceEx"></param>
         /// <param name="rasterDatasetName">栅格数据集名称,如"rds"</param>
         /// <returns></returns>
         public ESRI.ArcGIS.Geodatabase.IRasterDataset OpenRasterDataset(ESRI.ArcGIS.Geodatabase.IRasterWorkspaceEx rasterWorkspaceEx, string rasterDatasetName) {
             return rasterWorkspaceEx.OpenRasterDataset(rasterDatasetName);
         }

需要指出的是,当我们的数据是存储在SDE数据库,FileGeodatabase或PersonalGeodatabase时,要用IRasterWorkspaceEx,而不是IRasterWorkspace.

IRasterWorkspace与IRasterWorkspaceEx的区别

　　　　1)IRasterWorkspace主要是用来读取以文件格式存储在本地的栅格数据.

　　　　2)IRasteWorkspaceEx接口主要是用来读取GeoDatabase中的栅格数据集和栅格目录.

打开栅格目录

　　打开栅格目录需要用IRasterWorkspaceEx,可以从以上(打开栅格数据集的第20~27行获取IRasterWorkspaceEx对象,然后通过OpenRasterCatalog获取.如

 /// <summary>
         /// 打开栅格目录.
         /// </summary>
         /// <param name="rasterWorkspaceEx"></param>
         /// <param name="rasterCatalogName">栅格目录名,如rasterCatalogName="r_catalog"</param>
         /// <returns></returns>
         public ESRI.ArcGIS.Geodatabase.IRasterCatalog OpenRasterCatalog(ESRI.ArcGIS.Geodatabase.IRasterWorkspaceEx rasterWorkspaceEx, string rasterCatalogName) {
             return rasterWorkspaceEx.OpenRasterCatalog(rasterCatalogName);
         }

 打开栅格目录中的数据

 //打开栅格目录中的数据.
         ESRI.ArcGIS.Geodatabase.IRasterDataset GetRasterCatalogItem(ESRI.ArcGIS.Geodatabase.IRasterCatalog rasterCatalog, int objectId) {
             ESRI.ArcGIS.Geodatabase.IFeatureClass fc = (ESRI.ArcGIS.Geodatabase.IFeatureClass)rasterCatalog;
             ESRI.ArcGIS.Geodatabase.IRasterCatalogItem rCataItem = (ESRI.ArcGIS.Geodatabase.IRasterCatalogItem)fc.GetFeature(objectId);
             return rCataItem.RasterDataset;
         }