CAD文件有两种加载方式，一种是要素类图层的加载方式，另一种是像栅格图层一样加载。 1 要素类方式加载
IWorkspaceFactory pWorkspaceFactory = new CadWorkspaceFactoryClass(); IFeatureWorkspace pFeatureWorkspace = (IFeatureWorkspace) pWorkspaceFactory.OpenFromFile("C:\\path\\to\\CAD", 0); CAD加载方式一：分图层加载CAD文件（包括：点、线、面和注记） //打开一个要素集 IFeatureDataset pFeatureDataset = pFeatureWorkspace.OpenFeatureDataset("***.dwg"); IFeatureClassContainer pFeatureClassContainer = (IFeatureClassContainer) pFeatureDataset; IGroupLayer pGroupLayer = new GroupLayerClass(); pGroupLayer.Name = pFeatureDataset.Name; //遍历CAD文件中的每个要素 for (int i = 0; i < pFeatureClassContainer.ClassCount; i++) { IFeatureClass pFeatureClass = pFeatureClassContainer.get_Class(i); //加载注记图层【esriFTCoverageAnnotation】 if (pFeatureClass.FeatureType == esriFeatureType.esriFTCoverageAnnotation) { IFeatureLayer pFeatureLayer = new CadAnnotationLayerClass(); pFeatureLayer.Name = pFeatureClass.AliasName; pFeatureLayer.FeatureClass = pFeatureClass; pFeatureLayer.DataSourceType = "CAD Annotation Feature Class";//设置后Annotation的默认符号化方式是注记而不是点 pGroupLayer.Add(pFeatureLayer); } //加载点线面图层 else { IFeatureLayer pFeatureLayer = new FeatureLayerClass(); pFeatureLayer.Name = pFeatureClass.AliasName; pFeatureLayer.FeatureClass = pFeatureClass; pGroupLayer.Add(pFeatureLayer); } } pMap.AddLayer(pGroupLayer);2 像raster一样加载CAD文件
IWorkspaceFactory pWorkspaceFactory = new CadWorkspaceFactoryClass(); IFeatureWorkspace pFeatureWorkspace = (IFeatureWorkspace) pWorkspaceFactory.OpenFromFile("C:\\path\\to\\CAD", 0); ICadDrawingWorkspace pCadDrawingWorkspace = pFeatureWorkspace as ICadDrawingWorkspace; ICadDrawingDataset pCadDataset = pCadDrawingWorkspace.OpenCadDrawingDataset("***.dwg"); ICadLayer pCadLayer = new CadLayerClass(); pCadLayer.CadDrawingDataset = pCadDataset; pMap.AddLayer(pCadLayer);