C#arcengine更改GDB中要素数据集坐标系

您可以使用C# ArcObjects代码来更改GDB中要素数据集的坐标系。下面是一个简单的示例代码：

//打开工作空间
IWorkspaceFactory workspaceFactory = new FileGDBWorkspaceFactory();
IWorkspace workspace = workspaceFactory.OpenFromFile("C:\data.gdb", 0);

//获取要素数据集
IFeatureWorkspace featureWorkspace = workspace as IFeatureWorkspace;
IFeatureDataset featureDataset = featureWorkspace.OpenFeatureDataset("datasetName");

//获取要素类
IFeatureClass featureClass = featureDataset.OpenFeatureClass("className");

//获取要素类的空间参考信息
ISpatialReference spatialReference = featureClass.Fields.get_Field(featureClass.FindField(featureClass.ShapeFieldName)).GeometryDef.SpatialReference;

//创建新的空间参考对象
ISpatialReferenceFactory spatialReferenceFactory = new SpatialReferenceEnvironmentClass();
ISpatialReference newSpatialReference = spatialReferenceFactory.CreateProjectedCoordinateSystem(12345);

//更新数据集的空间参考
IDataset dataset = featureDataset as IDataset;
dataset.AlterSpatialReference(newSpatialReference);

//更新要素类的空间参考
IClassSchemaEdit classSchemaEdit = featureClass as IClassSchemaEdit;
classSchemaEdit.AlterSpatialReference(newSpatialReference);

在这个示例代码中，我们首先打开工作空间并获取要素数据集和要素类。然后，我们获取要素类的空间参考信息，并使用它创建新的空间参考对象。接下来，我们使用AlterSpatialReference方法更新数据集和要素类的空间参考。