【ArcObjects】地理数据库（gdb/mdb/要数数据集）中创建指定数据结构的要素类/表格

旧城等待， 2022-10-07 03:54 200阅读 0赞

# GDB/MDB中创建要素类、表格 #

1.  构造IFields  
    涉及`OBJECTID`字段、`Shape`字段及其他字段的设置，指定别名`AliasName_2`、类型`Type_2`
2.  创建要素类/表格
3.  修改要素类/表格的别名

> https://desktop.arcgis.com/en/arcobjects/latest/net/webframe.htm\#create\_an\_object\_class.htm

// 要素数据集中创建要素类
    tFeatureDataset.CreateFeatureClass(fcName, fields, null, null, esriFeatureType.esriFTSimple, "Shape", "");
    // featureclassWorkspace中创建表格
    fcWorkspace.CreateTable(tableName, fields, ocDescription.InstanceCLSID, null, "");

// 修改要素类别名
    IFeatureClass featureClass = fcWorkspace.OpenFeatureClass(fcName);
    IClassSchemaEdit tClassSchema = featureClass as IClassSchemaEdit;
    tClassSchema.AlterAliasName(fcAlias);
    
    // 修改表格别名
    IObjectClass table = fcWorkspace.OpenTable(tableName) as IObjectClass;
    IClassSchemaEdit tClassSchema = table as IClassSchemaEdit;
    tClassSchema.AlterAliasName(tableAlias);

# 完整代码 #

public IFields CreateFields(IWorkspace tWorkspace, string datasetName, string fcShape, ArrayList fieldsList)
    { 
        IFields fields = new FieldsClass();
        IFieldsEdit fieldsEdit = (IFieldsEdit)fields;
    
        IField oidField = new FieldClass();
        IFieldEdit oidFieldEdit = (IFieldEdit)oidField;
        oidFieldEdit.Name_2 = "OBJECTID";
        oidFieldEdit.AliasName_2 = "OBJECTID";
        oidFieldEdit.Type_2 = esriFieldType.esriFieldTypeOID;
        fieldsEdit.AddField(oidField);
    
        IField pField = new FieldClass();
        IFieldEdit pFieldEdit = (IFieldEdit)pField;
        pFieldEdit.Name_2 = "Shape";
        pFieldEdit.Type_2 = esriFieldType.esriFieldTypeGeometry;
    
        IGeometryDefEdit pGeoDef = new GeometryDefClass();
        IGeometryDefEdit pGeoDefEdit = pGeoDef as IGeometryDefEdit;
    
        IFeatureWorkspace fcWorkspace = tWorkspace as IFeatureWorkspace;
        IFeatureDataset tFeatureDataset = fcWorkspace.OpenFeatureDataset(datasetName);
        ISpatialReference pSpatialReference = GetSpatialReference(tFeatureDataset);
        pGeoDefEdit.SpatialReference_2 = pSpatialReference;
    
        switch (fcShape)
        { 
            case "点":
                pGeoDefEdit.GeometryType_2 = esriGeometryType.esriGeometryPoint;
                break;
            case "线":
                pGeoDefEdit.GeometryType_2 = esriGeometryType.esriGeometryPolyline;
                break;
            case "面":
                pGeoDefEdit.GeometryType_2 = esriGeometryType.esriGeometryPolygon;
                break;
        }
    
        pFieldEdit.GeometryDef_2 = pGeoDef;
        fieldsEdit.AddField(pField);
    
        foreach (ArrayList item in fieldsList)
        { 
            IField field = new FieldClass();
            IFieldEdit fieldEdit = (IFieldEdit)field;
    
            fieldEdit.Name_2 = item[0].ToString();
            fieldEdit.AliasName_2 = item[1].ToString();
            fieldEdit.IsNullable_2 = true;
    
            string fieldType = item[2].ToString();
            switch (fieldType.ToUpper())
            { 
                case "TEXT":
                case "CHAR":
                    fieldEdit.Type_2 = esriFieldType.esriFieldTypeString;
                    break;
                case "FLOAT":
                    fieldEdit.Type_2 = esriFieldType.esriFieldTypeSingle;
                    break;
                case "DOUBLE":
                    fieldEdit.Type_2 = esriFieldType.esriFieldTypeDouble;
                    break;
                case "SHORT":
                    fieldEdit.Type_2 = esriFieldType.esriFieldTypeSmallInteger;
                    break;
                case "LONG":
                case "INT":
                    fieldEdit.Type_2 = esriFieldType.esriFieldTypeInteger;
                    break;
                case "DATE":
                    fieldEdit.Type_2 = esriFieldType.esriFieldTypeDate;
                    break;
            }
    
    
            if (fieldEdit.Type == esriFieldType.esriFieldTypeString)
            { 
                fieldEdit.Length_2 = int.Parse(item[3].ToString());
            }
    
            fieldsEdit.AddField(field);
        }
    
        fields = (IFields)fieldsEdit;
    
        return fields;
    }
    
    
    public IFields CreateTableFields(IWorkspace tWorkspace, ArrayList fieldsList)
    { 
        IFields fields = new FieldsClass();
        IFieldsEdit fieldsEdit = (IFieldsEdit)fields;
    
        IField oidField = new FieldClass();
        IFieldEdit oidFieldEdit = (IFieldEdit)oidField;
        oidFieldEdit.Name_2 = "OBJECTID";
        oidFieldEdit.AliasName_2 = "OBJECTID";
        oidFieldEdit.Type_2 = esriFieldType.esriFieldTypeOID;
        fieldsEdit.AddField(oidField);
    
        foreach (ArrayList item in fieldsList)
        { 
            IField field = new FieldClass();
            IFieldEdit fieldEdit = (IFieldEdit)field;
    
            fieldEdit.Name_2 = item[0].ToString();
            fieldEdit.AliasName_2 = item[1].ToString();
            fieldEdit.IsNullable_2 = true;
    
            string fieldType = item[2].ToString();
            switch (fieldType.ToUpper())
            { 
                case "TEXT":
                case "CHAR":
                    fieldEdit.Type_2 = esriFieldType.esriFieldTypeString;
                    break;
                case "FLOAT":
                    fieldEdit.Type_2 = esriFieldType.esriFieldTypeSingle;
                    break;
                case "DOUBLE":
                    fieldEdit.Type_2 = esriFieldType.esriFieldTypeDouble;
                    break;
                case "SHORT":
                    fieldEdit.Type_2 = esriFieldType.esriFieldTypeSmallInteger;
                    break;
                case "LONG":
                case "INT":
                    fieldEdit.Type_2 = esriFieldType.esriFieldTypeInteger;
                    break;
                case "DATE":
                    fieldEdit.Type_2 = esriFieldType.esriFieldTypeDate;
                    break;
            }
    
    
            if (fieldEdit.Type == esriFieldType.esriFieldTypeString)
            { 
                fieldEdit.Length_2 = int.Parse(item[3].ToString());
            }
    
            fieldsEdit.AddField(field);
        }
    
        fields = (IFields)fieldsEdit;
    
        return fields;
    }
    
    public void CreateDataset(IWorkspace tWorkspace, string datasetName)
    { 
        // 若工作空间不存在数据集时，创建之
        IWorkspace2 tWorkspace2 = tWorkspace as IWorkspace2;
        IFeatureWorkspace fcWorkspace = tWorkspace as IFeatureWorkspace;
    
        if (!tWorkspace2.get_NameExists(esriDatasetType.esriDTFeatureDataset, datasetName))
        { 
            ISpatialReferenceFactory3 spatialReferenceFactory = new SpatialReferenceEnvironmentClass();
            IProjectedCoordinateSystem geographicCoordinateSystem = spatialReferenceFactory.CreateProjectedCoordinateSystem(4526);  // CGCS2000
    
            ISpatialReference3 spatialReference = geographicCoordinateSystem as ISpatialReference3;
            IVerticalCoordinateSystem verticalCoordinateSystem = spatialReferenceFactory.CreateVerticalCoordinateSystem((int)esriSRVerticalCSType.esriSRVertCS_YellowSea1985);  // 黄海1985高程
            spatialReference.VerticalCoordinateSystem = verticalCoordinateSystem;
    
            fcWorkspace.CreateFeatureDataset(datasetName, spatialReference);
        }
    }
    
    public static ISpatialReference GetSpatialReference(IFeatureDataset pDataset)
    { 
        IGeoDataset pGeoDataset = pDataset as IGeoDataset;
        ISpatialReference pSpatialReference = pGeoDataset.SpatialReference;
        return pSpatialReference;
    }
    
    public void CreateFeatureClass(IWorkspace tWorkspace, string datasetName, string fcName, string fcAlias, IFields fields)
    { 
         if ((tWorkspace as IWorkspace2).get_NameExists(esriDatasetType.esriDTFeatureClass, fcName)) { 
             return;
         }
         IFeatureWorkspace fcWorkspace = tWorkspace as IFeatureWorkspace;
         IFeatureDataset tFeatureDataset = fcWorkspace.OpenFeatureDataset(datasetName);
         
    
         tFeatureDataset.CreateFeatureClass(fcName, fields, null, null, esriFeatureType.esriFTSimple, "Shape", "");
         // 修改别名
         IFeatureClass featureClass = fcWorkspace.OpenFeatureClass(fcName);
         IClassSchemaEdit tClassSchema = featureClass as IClassSchemaEdit;
         tClassSchema.AlterAliasName(fcAlias);
     }
    
     public void CreateTable(IWorkspace tWorkspace, string tableName, string tableAlias, IFields fields)
     { 
         if ((tWorkspace as IWorkspace2).get_NameExists(esriDatasetType.esriDTTable, tableName))
         { 
             return;
         }
         IFeatureWorkspace fcWorkspace = tWorkspace as IFeatureWorkspace;
        
         IObjectClassDescription ocDescription = new ObjectClassDescriptionClass();
         //IFields fields = ocDescription.RequiredFields;
         //IFieldsEdit fieldsEdit = (IFieldsEdit)fields;
    
         fcWorkspace.CreateTable(tableName, fields, ocDescription.InstanceCLSID, null, "");
         
         // 修改别名
         IObjectClass table = fcWorkspace.OpenTable(tableName) as IObjectClass;
         IClassSchemaEdit tClassSchema = table as IClassSchemaEdit;
         tClassSchema.AlterAliasName(tableAlias);
     }

# Table vs Objects Classes #

## IFieldEdit.AliasName\_2 ##

> https://developers.arcgis.com/enterprise-sdk/api-reference/net/esriGeoDatabase/IField/

This is only supported on fields from object classes and feature classes that are registered with the geodatabase; Personal, File or ArcSDE geodatabases. For fields coming from other data sources (shapefiles, coverages, etc) the AliasName will be the same string as the field name.

## ITable AlterAliasName ##

> https://desktop.arcgis.com/en/arcobjects/latest/net/webframe.htm\#create\_an\_object\_class.htm

**Tables vs. object classes**

The terms “table” and “object class” are often used interchangeably in the context of the geodatabase, but there are differences between the two. An object class is a special type of table, specifically one that has been registered with the geodatabase (meaning that the geodatabase system tables have references to it). **Tables that are not object classes do not exhibit any geodatabase behavior**, for example, they cannot have **aliases**, subtypes or domains assigned to their fields.

When creating a table in ArcCatalog, an object class is created by default, but the class identifier (CLSID) parameter of CreateTable can be used to create a table that is not registered with the geodatabase. Rather than passing in a valid unique identifier (UID) instance (this is discussed in more detail in the parameters section later in this topic), a null value indicates that an unregistered table should be created.