gis 导出 dwg，shp

当我们在webgis 想要把某个地块或者多个地块导出dwg或者shp文件的时候怎么办？这个时候最好就是用后台的方式。首先把web gis上的graphic 的polygon提取为坐标的形式（类似于x,y x,y x,y），如果这个图形你知道在某个sde库的，也可以提取它的主键属性信息，方便在后台直接查询，减少坐标传输，地块特别大的很麻烦。后台首先要把坐标存到一个内存的featureclass

         //创建内存图层
         private IFeatureClass createMemoryFeatureClass(string coord)
         {
             IField oField = new FieldClass();
             IFields oFields = new FieldsClass();
             IGeometryDef geometryDef = new GeometryDefClass();

             IWorkspaceFactory workspaceFactory = new InMemoryWorkspaceFactoryClass();
             IWorkspaceName workspaceName = workspaceFactory.Create("", "MyWorkspace", null, );
             IName name = (IName)workspaceName;
             IWorkspace inmemWorkSpace = (IWorkspace)name.Open();

             IFieldsEdit oFieldsEdit = null;
             IFieldEdit oFieldEdit = null;

             IFeatureLayer oFeatureLayer = null;
             IFeatureClass outputFeatureClass = null;
             IFeatureCursor outputFeatureCursor = null;
             try
             {

                 oFieldsEdit = oFields as IFieldsEdit;
                 oFieldEdit = oField as IFieldEdit;

                 IGeometryDefEdit geometryDefEdit = (IGeometryDefEdit)geometryDef;
                 geometryDefEdit.AvgNumPoints_2 = ;
                 geometryDefEdit.GeometryType_2 = esriGeometryType.esriGeometryPolygon;
                 geometryDefEdit.GridCount_2 = ;
                 geometryDefEdit.HasM_2 = false;
                 geometryDefEdit.HasZ_2 = false;

                 //ISpatialReferenceFactory ispfac = new SpatialReferenceEnvironmentClass();
                 //IGeographicCoordinateSystem igeocoorsys = ispfac.CreateGeographicCoordinateSystem((int)esriSRGeoCSType.esriSRGeoCS_WGS1984);
                 //igeocoorsys.SetDomain(76000, 180000, 0, 104000);
                 geometryDefEdit.SpatialReference_2 = getSpatialReference();

                 oFieldEdit.Name_2 = "SHAPE";
                 oFieldEdit.Type_2 = esriFieldType.esriFieldTypeGeometry;
                 oFieldEdit.GeometryDef_2 = geometryDef;
                 oFieldEdit.IsNullable_2 = true;
                 oFieldEdit.Required_2 = true;
                 oFieldsEdit.AddField(oField);

                 outputFeatureClass = (inmemWorkSpace as IFeatureWorkspace).CreateFeatureClass("selectedPoints", oFields, null, null, esriFeatureType.esriFTSimple, "SHAPE", "");
                 outputFeatureCursor = outputFeatureClass.Insert(true);
                 IFeatureBuffer outputFeatureBuffer = outputFeatureClass.CreateFeatureBuffer();

                 IWorkspaceEdit inmemWorkspaceEdit = inmemWorkSpace as IWorkspaceEdit;
                 inmemWorkspaceEdit.StartEditing(false);      //Start Editing
                 inmemWorkspaceEdit.StartEditOperation();
                 if (coord != "")
                 {
                     outputFeatureBuffer.Shape = ArcGISUtil.StringToPolygon(coord);
                     outputFeatureCursor.InsertFeature(outputFeatureBuffer);

                 }
                 inmemWorkspaceEdit.StopEditOperation();
                 inmemWorkspaceEdit.StopEditing(true);

                 IGeoDataset outputGeodataset = (IGeoDataset)outputFeatureClass;

                 oFeatureLayer = new FeatureLayerClass();
                 oFeatureLayer.FeatureClass = outputFeatureClass;
                 oFeatureLayer.Name = "fa";
             }
             catch (Exception e)
             {
                 System.Diagnostics.Trace.WriteLine(e.StackTrace);
             }
             finally
             {
                 ArcGISUtil.FinalReleaseComObject(outputFeatureCursor);
                 ArcGISUtil.FinalReleaseComObject(oField);
                 ArcGISUtil.FinalReleaseComObject(oFields);
                 ArcGISUtil.FinalReleaseComObject(geometryDef);
                 ArcGISUtil.FinalReleaseComObject(workspaceFactory);
                 ArcGISUtil.FinalReleaseComObject(outputFeatureClass);
             }
             return oFeatureLayer.FeatureClass;
         }

得到的内存图层，如果是要转shp，可以直接转，如果是要转dwg，先要转为gdb，直接转dwg会失败，目前找不到原因。

  //要素转shp 或者gdb
         private void feature2GDB(IFeatureClass sourceFeatureClass, IQueryFilter pQueryFilter, string name, string type, string _fileShortName)
         {
             try
             {
                 string fileShortName = string.Empty;
                 if (type == "gdb")
                 {
                     fileShortName = _fileShortName;                  

                 }
                 else
                 {
                     fileShortName = name;
                 }

                 string parentDirectory = HttpContext.Current.Server.MapPath(@"\Checkservices\gdbpath\");

                 IFeatureClassName sourceFeatureClassName = new FeatureClassNameClass();
                 IDataset pOutDataset = (IDataset)sourceFeatureClass;
                 sourceFeatureClassName = (IFeatureClassName)pOutDataset.FullName;

                 IWorkspaceFactory wsf = null;
                 if (type == "gdb")
                 {
                     wsf = new FileGDBWorkspaceFactoryClass();
                 }
                 else if (type == "shp")
                 {
                     wsf = new ShapefileWorkspaceFactoryClass();
                 }

                 IWorkspaceName pInWorkspaceName = new WorkspaceNameClass();
                 pInWorkspaceName = wsf.Create(parentDirectory, name, null, );

                 IFeatureClassName pInFeatureClassName = new FeatureClassNameClass();
                 IDatasetName pInDatasetClassName;
                 pInDatasetClassName = (IDatasetName)pInFeatureClassName;
                 pInDatasetClassName.Name = fileShortName;
                 pInDatasetClassName.WorkspaceName = pInWorkspaceName;

                 long iCounter;
                 IFields pOutFields, pInFields;
                 IField pGeoField;
                 IEnumFieldError pEnumFieldError = null;
                 pInFields = sourceFeatureClass.Fields;
                 IFieldChecker pFieldChecker = new FieldChecker();
                 //pFieldChecker.InputWorkspace = pOutDataset.Workspace;

                 pFieldChecker.Validate(pInFields, out pEnumFieldError, out pOutFields);
                 pGeoField = null;
                 for (iCounter = ; iCounter < pOutFields.FieldCount; iCounter++)
                 {
                     if (pOutFields.get_Field((int)iCounter).Type == esriFieldType.esriFieldTypeGeometry)
                     {
                         pGeoField = pOutFields.get_Field((int)iCounter);
                         break;
                     }
                 }

                 IGeometryDef pOutGeometryDef;
                 IGeometryDefEdit pOutGeometryDefEdit;
                 pOutGeometryDef = pGeoField.GeometryDef;
                 pOutGeometryDefEdit = (IGeometryDefEdit)pOutGeometryDef;

                 IFeatureDataConverter pShpToClsConverter = new FeatureDataConverterClass();
                 pShpToClsConverter.ConvertFeatureClass(sourceFeatureClassName, pQueryFilter,
                     null, pInFeatureClassName, pOutGeometryDef, pOutFields, "", , );

                 ArcGISUtil.FinalReleaseComObject(wsf);
                 ArcGISUtil.FinalReleaseComObject(pInWorkspaceName);
                 ArcGISUtil.FinalReleaseComObject(pInFeatureClassName);
                 ArcGISUtil.FinalReleaseComObject(pFieldChecker);
                 ArcGISUtil.FinalReleaseComObject(pShpToClsConverter);
             }
             catch (Exception e)
             {
                 System.Diagnostics.Trace.WriteLine(e.StackTrace);
             }
         }

         private IFeatureClass openFeatureClass(String layerName, String sde)
         {
             IFeatureClass fc = null;
             try
             {
                 fc = SdeConnectManager.getFeatureClass(layerName, sde);
             }
             catch
             {
                 return null;
             }
             return fc;
         }

要转dwg可以直接调用AO接口

         private void gdb2Cad(string gdbfilePath, string cadfilePath, int num = )
         {
             Geoprocessor gp = new Geoprocessor();
             try
             {
                 ExportCAD tool = new ExportCAD();
                 tool.in_features = gdbfilePath;
                 tool.Output_File = cadfilePath;
                 tool.Output_Type = "DWG_R2004";
                 gp.Execute(tool, null);
             }
             catch (Exception e)
             {
                 System.Diagnostics.Trace.WriteLine(e.StackTrace);
                 System.Diagnostics.Trace.Write("dwg");
             }
         }

但是如果导出dwg图形有注记的话，AO这个方法就行不通了，貌似arcgis对导出dwg图形带标注支持的不好，后面会有专门的文章讲怎么导出带有注记的dwg。