数据的转换(shp sde mdb 之间的转换)

调用用下面的方法可以将要素类从sde导出到shp或者mdb 或者从三个中的任意一个导出到另外一个。方法是：

/// <summary>
        /// 将一个要素类从一个工作空间转移到另外一个工作空间
        /// 注意目标工作空间不能有改要素类，必须先清除  
        /// </summary>
        /// <param name="sourceWorkspace">源工作空间</param>
        /// <param name="targetWorkspace">目标工作空间</param>
        /// <param name="nameOfSourceFeatureClass">源要素类名</param>
        /// <param name="nameOfTargetFeatureClass">目标要素类名</param>
        public void IFeatureDataConverter_ConvertFeatureClass(IWorkspace sourceWorkspace, IWorkspace targetWorkspace, string nameOfSourceFeatureClass, string nameOfTargetFeatureClass)
        {            
            //create source workspace name   
            IDataset sourceWorkspaceDataset = (IDataset)sourceWorkspace;
            IWorkspaceName sourceWorkspaceName = (IWorkspaceName)sourceWorkspaceDataset.FullName;
            //create source dataset name   
            IFeatureClassName sourceFeatureClassName = new FeatureClassNameClass();
            IDatasetName sourceDatasetName = (IDatasetName)sourceFeatureClassName;
            sourceDatasetName.WorkspaceName = sourceWorkspaceName;
            sourceDatasetName.Name = nameOfSourceFeatureClass;
            //create target workspace name   
            IDataset targetWorkspaceDataset = (IDataset)targetWorkspace;
            IWorkspaceName targetWorkspaceName = (IWorkspaceName)targetWorkspaceDataset.FullName;
            //create target dataset name   
            IFeatureClassName targetFeatureClassName = new FeatureClassNameClass();
            IDatasetName targetDatasetName = (IDatasetName)targetFeatureClassName;
            targetDatasetName.WorkspaceName = targetWorkspaceName;
            targetDatasetName.Name = nameOfTargetFeatureClass;
            //Open input Featureclass to get field definitions.   
            ESRI.ArcGIS.esriSystem.IName sourceName = (ESRI.ArcGIS.esriSystem.IName)sourceFeatureClassName;
            IFeatureClass sourceFeatureClass = (IFeatureClass)sourceName.Open();

//Validate the field names because you are converting between different workspace types.   
            IFieldChecker fieldChecker = new FieldCheckerClass();
            IFields targetFeatureClassFields;
            IFields sourceFeatureClassFields = sourceFeatureClass.Fields;
            IEnumFieldError enumFieldError;
            // Most importantly set the input and validate workspaces!     
            fieldChecker.InputWorkspace = sourceWorkspace;
            fieldChecker.ValidateWorkspace = targetWorkspace;
            fieldChecker.Validate(sourceFeatureClassFields, out enumFieldError, out targetFeatureClassFields);
            // Loop through the output fields to find the geomerty field   
            IField geometryField;
            for (int i = 0; i < targetFeatureClassFields.FieldCount; i++)
            {
                if (targetFeatureClassFields.get_Field(i).Type == esriFieldType.esriFieldTypeGeometry)
                {
                    geometryField = targetFeatureClassFields.get_Field(i);
                    // Get the geometry field's geometry defenition            
                    IGeometryDef geometryDef = geometryField.GeometryDef;
                    //Give the geometry definition a spatial index grid count and grid size        
                    IGeometryDefEdit targetFCGeoDefEdit = (IGeometryDefEdit)geometryDef;
                    targetFCGeoDefEdit.GridCount_2 = 1;
                    targetFCGeoDefEdit.set_GridSize(0, 0);
                    //Allow ArcGIS to determine a valid grid size for the data loaded      
                    targetFCGeoDefEdit.SpatialReference_2 = geometryField.GeometryDef.SpatialReference;
                    // we want to convert all of the features   
                    IQueryFilter queryFilter = new QueryFilterClass();
                    queryFilter.WhereClause = "";
                    // Load the feature class     
                    IFeatureDataConverter fctofc = new FeatureDataConverterClass();
                    IEnumInvalidObject enumErrors = fctofc.ConvertFeatureClass(sourceFeatureClassName, queryFilter, null, targetFeatureClassName, geometryDef, targetFeatureClassFields, "", 1000, 0);
                    break;
                }
            }

}

只要设定了工作空间，不管工作空间是文件的 数据库的 还是什么的，可以自由转换。

比如我要将sde的要素类导出成shp文件，如下：

public void Export_Shp(IFeatureClass pFeatClass, string path)
        {
            IDataset pDataSet = pFeatClass as IDataset;
            IWorkspace pWorkspace = pDataSet.Workspace;

string strShapeFolder = path;
            string fileName = pFeatClass.AliasName;

string fullFileName = path + "\\" + fileName + ".shp";
            fullFileName = fullFileName.Replace(@"\\", @"\");
            if (File.Exists(fullFileName))
            { //如果已经存在就先删除
                DirectoryInfo di = new DirectoryInfo(path);
                FileInfo[] fis = di.GetFiles(fileName + "*");
                foreach (FileInfo fi in fis)
                {
                    fi.Delete();
                }
            }

IWorkspaceFactory pWSF = new ShapefileWorkspaceFactoryClass();
            IFeatureWorkspace pWS = (IFeatureWorkspace)pWSF.OpenFromFile(strShapeFolder, 0);

this.IFeatureDataConverter_ConvertFeatureClass(pWorkspace, (IWorkspace)pWS, pFeatClass.AliasName, fileName);

}