方法一、

            IWorkspaceFactory pWorkspaceFactory;
            IFeatureWorkspace pFeatureWorkspace;
            IFeatureLayer pFeatureLayer;
            IFeatureDataset pFeatureDataset;
            //打开CAD数据集
            pWorkspaceFactory = new CadWorkspaceFactoryClass();
            pFeatureWorkspace = (IFeatureWorkspace)pWorkspaceFactory.OpenFromFile(directoryPath, 0);
            //打开一个要素集
            pFeatureDataset = pFeatureWorkspace.OpenFeatureDataset(fileName);
            //IFeaturClassContainer可以管理IFeatureDataset中的每个要素类  
            IFeatureClassContainer pFeatureClassContainer = (IFeatureClassContainer)pFeatureDataset;
            //对CAD文件中的要素进行遍历处理
            for (int i = 0; i < pFeatureClassContainer.ClassCount – 1; i++)
            {
                IFeatureClass pFeatureClass = pFeatureClassContainer.get_Class(i);
                if (pFeatureClass.FeatureType == esriFeatureType.esriFTAnnotation)
                {
                    //如果是注记，则添加注记层
                    pFeatureLayer = new CadAnnotationLayerClass();
                }
                else//如果是点、线、面，则添加要素层
                {
                    pFeatureLayer = new FeatureLayerClass();
                    pFeatureLayer.Name = pFeatureClass.AliasName;
                    pFeatureLayer.FeatureClass = pFeatureClass;

                    this.axmc_Main.Map.AddLayer(pFeatureLayer);
                    this.axmc_Main.ActiveView.**();
                }
            }

方法二、

            //–定义工作空间，并用CadWorkspaceFactoryClass()实例化它
            IWorkspaceFactory pWorkspaceFactory = new CadWorkspaceFactoryClass();
            //–打开相应的工作空间，并赋值给要素空间，OpenFromFile（）
            //–中的参数为CAD文件夹的路径
            IFeatureWorkspace pFeatureWorkspace = pWorkspaceFactory.OpenFromFile(directoryPath, 0) as IFeatureWorkspace;
            /*–打开线要素类，如果要打开点类型的要素，需要把下边的代码该成：
            *– IFeatureClass pFeatureClass = pFeatureWorkspace.OpenFeatureClass (fileName + “:point”);
            *– 由此可见fileName为CAD图的名字，后边加上要打开的要素类的类型，中间用冒号　　
            *– 隔开，大家可以想想多边形和标注是怎么打开的。 */
            //point          polyline
            IFeatureClass pFeatureClass = pFeatureWorkspace.OpenFeatureClass(fileName + “:point”);
            IFeatureLayer pFeatureLayer = new FeatureLayerClass();
            pFeatureLayer.FeatureClass = pFeatureClass;
            this.axmc_Main.Map.AddLayer(pFeatureLayer);
            this.axmc_Main.ActiveView.**();

方法三、

            /*–下边的两行代码是定义一个CAD工作空间，然后打开它，但这次不是赋值给
            –IFeatureWorkspace对象,而是赋值给IWorkspace定义的对象*/
            IWorkspaceFactory pWorkspaceFactory = new CadWorkspaceFactoryClass();
            IWorkspace pWorkspace = pWorkspaceFactory.OpenFromFile(directoryPath, 0);
            //–定义一个CAD画图空间，并把上边打开的工作空间赋给它
            ICadDrawingWorkspace pCadDrawingWorkspace = pWorkspace as ICadDrawingWorkspace;
            //–定义一个CAD的画图数据集，并且打开上边指定的工作空间中一幅CAD图
            //–然后赋值给CAD数据集
            ICadDrawingDataset pCadDrawingDataset = pCadDrawingWorkspace.OpenCadDrawingDataset(fileName);
            //–通过ICadLayer类，把上边得到的CAD数据局赋值给ICadLayer类对象的
            //–CadDrawingDataset属性
            ICadLayer pCadLayer = new CadLayerClass();
            pCadLayer.CadDrawingDataset = pCadDrawingDataset;
            //–利用MapControl加载CAD层
            this.axmc_Main.Map.AddLayer(pCadLayer);
            this.axmc_Main.ActiveView.**();

方法四、

            IWorkspaceFactory pWorkspaceFactory = new CadWorkspaceFactoryClass();
            IFeatureWorkspace pFeatureWorkspace = pWorkspaceFactory.OpenFromFile(directoryPath, 0) as IFeatureWorkspace;
            IFeatureDataset pFeatureDataset = pFeatureWorkspace.OpenFeatureDataset(fileName);
            IFeatureClassContainer pFeatureClassContainer = (IFeatureClassContainer)pFeatureDataset;

            for (int i = 0; i < pFeatureClassContainer.ClassCount – 1; i++)
            {
                IFeatureClass pFeatureClass = pFeatureClassContainer.get_Class(i);
                IFeatureLayer pFeatureLayer = new FeatureLayerClass();
                pFeatureLayer.FeatureClass = pFeatureClass;
                //ICadLayer pCadLayer = new CadLayerClass();
                //pCadLayer = pFeatureLayer as ICadLayer;
                this.axmc_Main.Map.AddLayer(pFeatureLayer);
                this.axmc_Main.ActiveView.**();
            }

方法五、

            //Add passed file to MapControl
            ICadDrawingDataset pCadDrawingDataset = GetCadDrawingDataset(directoryPath, fileName);
            if (pCadDrawingDataset == null) return;
            ICadLayer pCadLayer = new CadLayerClass();
            pCadLayer.CadDrawingDataset = pCadDrawingDataset;
            pCadLayer.Name = fileName;
            this.axmc_Main.AddLayer(pCadLayer, 0);

        /// <summary>
        /// 获取记录集
        /// </summary>
        /// <param name=”directoryPath”></param>
        /// <param name=”fileName”></param>
        /// <returns></returns>
        private ICadDrawingDataset GetCadDrawingDataset(string directoryPath, string fileName)
        {
            //Create a WorkspaceName object
            IWorkspaceName pWorkspaceName = new WorkspaceNameClass();
            pWorkspaceName.WorkspaceFactoryProgID = “esriDataSourcesFile.CadWorkspaceFactory”;
            pWorkspaceName.PathName = directoryPath;

            //Create a CadDrawingName object
            IDatasetName pDatasetName = new CadDrawingNameClass();
            pDatasetName.Name = fileName;
            pDatasetName.WorkspaceName = pWorkspaceName;

            //Open the CAD drawing
            IName pName = (IName)pDatasetName;
            return (ICadDrawingDataset)pName.Open();
        }

需要注意

如果你的ArcGIS版本是V9.2的话,可能是因为你的文件名中含有中文字符的原因.据我所知,在ArcGIS9.2中无法显示文件名含有中文字符的CAD文件.你可以在ArcMap中直接打开试试,如果也无法显示的话,可能是文件名的问题(注:路径中也不能含有中文字符).

转载自:http://www.gisforum.net/bbs/dispbbs.asp?boardid=35&id=145238