C# + ArcEngine通过图层名获取对应数据集

可以通过以下代码实现：

//获取图层名为"LayerName"的图层
ESRI.ArcGIS.Carto.ILayer layer = null;
for (int i = 0; i < mapControl.LayerCount; i++)
{
    if (mapControl.get_Layer(i).Name == "LayerName")
    {
        layer = mapControl.get_Layer(i);
        break;
    }
}

//获取该图层对应的数据集
if (layer is ESRI.ArcGIS.Carto.IFeatureLayer)
{
    ESRI.ArcGIS.Carto.IFeatureLayer featureLayer = (ESRI.ArcGIS.Carto.IFeatureLayer)layer;
    ESRI.ArcGIS.Geodatabase.IDataset dataset = featureLayer.FeatureClass as ESRI.ArcGIS.Geodatabase.IDataset;
    //在这里对数据集进行操作
}

其中，`mapControl`为ArcEngine中的地图控件，可以根据实际情况进行替换。

相关问题

C#arcengine新建图层

你可以使用 ArcObjects 中的 IMap 和 IFeatureLayer 接口来新建图层。下面是一个示例代码：

// 获取当前地图
IMap map = ArcMap.Document.FocusMap;

// 创建一个要素工厂
IFeatureFactory featureFactory = new FeatureFactoryClass();

// 创建一个要素集合
IFeatureClass featureClass = featureFactory.CreateFeatureClass("FeatureClass", null, null, null, esriFeatureType.esriFTSimple, "Shape", "");

// 创建一个要素图层
IFeatureLayer featureLayer = new FeatureLayerClass();
featureLayer.FeatureClass = featureClass;
featureLayer.Name = "FeatureLayer";

// 将新图层添加到地图中
map.AddLayer(featureLayer);

以上代码会创建一个名为 "FeatureLayer" 的新图层，并将其添加到当前地图中。你可以根据需要修改代码中的参数来创建不同类型的图层。

C#arcengine更改GDB中要素数据集坐标系

在C# ArcEngine中更改GDB中要素数据集的坐标系，可以按照以下步骤操作：

1. 打开要素数据集所在的GDB文件：

IWorkspaceFactory workspaceFactory = new FileGDBWorkspaceFactory();
IWorkspace workspace = workspaceFactory.OpenFromFile(@"C:\data\myGDB.gdb", 0);

2. 获取要素数据集：

IFeatureWorkspace featureWorkspace = workspace as IFeatureWorkspace;
IFeatureDataset featureDataset = featureWorkspace.OpenFeatureDataset("myFeatureDataset");

3. 获取要素数据集的描述对象：

IDataset dataset = featureDataset as IDataset;
IObjectClassDescription objectClassDescription = new FeatureClassDescriptionClass();
IFields fields = null;
IUID uid = objectClassDescription.CLSID;
IEnumDataset enumDataset = featureDataset.Subsets;
enumDataset.Reset();
IDataset subsetDataset = enumDataset.Next();
while (subsetDataset != null)
{
    if (subsetDataset is IFeatureClass)
    {
        IFeatureClass featureClass = subsetDataset as IFeatureClass;
        if (featureClass.AliasName == "myFeatureClass")
        {
            fields = featureClass.Fields;
            uid = featureClass.ClassID;
            break;
        }
    }
    subsetDataset = enumDataset.Next();
}

4. 创建新的要素类，并设置其坐标系：

IFeatureClassDescription newFeatureClassDescription = new FeatureClassDescriptionClass();
IObjectClassDescription newObjectClassDescription = newFeatureClassDescription as IObjectClassDescription;
IFieldsEdit newFieldsEdit = new FieldsClass();
IFields newFields = fields;
newFieldsEdit.Clone(ref newFields);

IWorkspaceEdit workspaceEdit = workspace as IWorkspaceEdit;
bool hasParent = dataset.Category == "Feature Dataset";
IObjectClass newObjectClass = featureDataset.CreateFeatureClass("newFeatureClass", newFieldsEdit, uid, null, esriFeatureType.esriFTSimple, "SHAPE", "");
IDataset newDataset = newObjectClass as IDataset;
IGeoDataset geoDataset = newDataset as IGeoDataset;
ISpatialReferenceFactory spatialReferenceFactory = new SpatialReferenceEnvironmentClass();
ISpatialReference newSpatialReference = spatialReferenceFactory.CreateProjectedCoordinateSystem(3857); //设置新的坐标系
geoDataset.SpatialReference = newSpatialReference;

需要注意的是，更改坐标系可能会影响到数据的准确性和精度，建议在更改前备份数据并谨慎操作。