Question

如何使用Name对象，包括WorkspaceNames和DatasetNames

Answer 1

一、Name对象
Name对象是一个代表性对象。通过使用Name对象，可以访问它所代表的对象的一些基本属性，而不用将整个对象调入内存，如果需要用到Name对象所代表的对象本身，可以通过Name来获取它。
Name对象可以应用于Tables，FeatureClasses和Workspaces。

Name:
1、WorkspaceName
2、DatasetName
1>RelationshipClassName
2>FeatureDatasetName
3>RasterDatasetName
4>TinName
5>TableName
△－－FeatureClassName
使用Name对象最重要的一点是通过Name来获取所代表的对象，要访问Name子类里的任何对象，使用IName接口的Open方法。
示例：查找某个数据集并打开它
public void OpenCities()
{
IWorkspaceFactory pWSFactory;
IWorkspace pWS;
IEnumDatasetName pEnumDSNames;
IDatasetName pDSName;
IFeatureClass pCities;

pWSFactory = new ShapefileWorkspaceFactoryClass();
pWS = pWSFactory.OpenFromFile("C:\\Data\\Africa", 0);
pEnumDSNames = pWS.DatasetNames(esriDatasetType.esriDTFeatureClass);//feature class
pDSName = pEnumDSNames.Next();
while (pDSName != null)
{
if (pDSName.Name == "AfricanCities")
{
IName pName = pDSName as IName;
pCities = pName.Open() as IFeatureClass;
return;
}
pDSName = pEnumDSNames.Next();
}

二、使用DataSetNames

Name对象的一个常用用法是用来在磁盘中新建数据集时指定名字。例如，在数据转换过程中的输入输出参数中，使用DatasetName对象即可，而不必
用dataset对象。DatasetName的所有子类都是可以用New关键字新建的CoClass，一旦创建好就可以设置Name属性来代表数据集。
示例：在C:\Data下创建一个新表PositianFroys.dbf。
IWorkspaceFactory pShapeWSFactory;
IWorkspaceName pWorkName;
IDatasetName pTableName;

pShapeWSFactory = new ShapefileWorkspaceFactoryClass();
pWorkName = pShapeWSFactory.Create("C:\\", "Data", null, 0);
pTableName = new TableNameClass();
pTableName.WorkspaceName = pWorkName;
pTable.Name = "PositianFroys.dbf";

三、数据的转换、输出和装载

FeatureDataConverter是一个能将要素类、要素集或表转换成其它数据集的CoClass，它不仅可以转换单个的要素类或表，也可以转换
整个数据集（如ArcInfo
Coverage）。FeatureDataConverter对象能够使数据在geodatabase，shapefile和coverages之间转
换支持大多数的数据类型（除了标注）。在把数据引入geodatabase时，可以指定数据的区别；对ArcSDE
Geodatabase还可以通过配置ArcSDE的某些关键字来指定存储参数。
ExportOperation是一个用于输出要素类或表的CoClass。它提供的功能与要素数据转换器大体相似，但是形式更简单。在ArcMap的目录表中右击一个图层时就是调用了这个数据输出函数。
ObjectLoader用于向表（或要素类）中追加一个表（或要素类）。IObjectLoader只包含一个方法－－LoadObjects。

四、验证字段和记录

FieldChecker对象可以用来验证一个字段集，这对于在不同格式间转换数据时很有用，因为不同格式的数据集字段名可能不通用。
FieldChecker遇到非法字段名时能够根据一定的标准（如加底线UID）来纠正错误从而产生一个合法的字段集。在把数据转换成
Geodatabase格式时，FieldChecker将为Geometry字段和OID字段生成标准的名字（Shape和OBJECTID)。
在用ObjectLoader或FeatureDataConverter装载或者转换要素时，非法对象将以枚举的形式被返回（IEnumInvalidObject），通过查看这个枚举，很容易知道哪些对象不能被装载或转换。

五、使用Feature Data Converter
IFeatureDataConverter接口有3个方法用于转换数据：
1、ConvertFeatureClass
2、ConvertFeatureDataset
3、ConvertTable

public IEnumInvalidObject ConvertFeatureClass (
IFeatureClassName InputDatasetName,
IQueryFilter InputQueryFilter,
IFeatureDatasetName outputFDatasetName,
IFeatureClassName outputFClassName,
IGeometryDef OutputGeometryDef,
IFields OutputFields,
string configKey,
int FlushInterval,
int parentHWND
);
InputDatasetName－－IFeatureClassName用于指定转换的要素类的一个Name对象；
InputQueryFilter－－IQueryFilter用于过滤要转换的要素的QueryFilter对象；
outputFDatasetName－－IFeatureDatasetName要素类输出的新数据集成现存数据集的Name对象；
outputFClassName－－IFeatureClassName新输出的要素类的Name对象；
OutputGeometryDef－－用于指定输出要素类的空间参考信息的GeometryDef对象。如果知道为null就使用输出的要素集成输入的要素类的空间参考信息。
OutputFields－－IFields用于指定输出要素类的字段集。如果把要素类简单的输出为同样的格式，可以使用输入的要素类的字段集。如果格式有变化，建议使用FieldChecker以确保输出的格式有效；
configKey－－string用于指定ArcSDE配置关键字的字符串；
FlushInterval－－在输出到Geodatabase时用于指定把要素转换到新的要素类时的区间整数值；
parentHWND－－指定应用程序的窗口句柄；

示例：//IFeatureDataConverter ConvertFeatureClass Example(From .NET Help)

//e.g., nameOfSourceFeatureClass = "ctgFeatureshp.shp"
// nameOfTargetFeatureClass = "ctgFeature"
public void
IFeatureDataConverter_ConvertFeatureClass_Example(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;
}
}
}