ae9.2中加载显示cad文件

在论坛中有很多人提到ae9.2中不能加载显示cad，本人细心研究了一下，ae9.1和ae9.2加载cad的方式有点不同，现把代码贡献出来，共大家参考（本人已测试过，可用）

  private void OpenCadFile()
        { 
             //设置workspace
            IWorkspaceFactory  pWorkspaceFact=new CadWorkspaceFactoryClass();
            //Open the Workspace
            IWorkspace  pWorkspace;
            pWorkspace = pWorkspaceFact.OpenFromFile(@"E:\", 0);

            //设置CadDrawingWorkspace
            ICadDrawingWorkspace pCadDwgWorkspace = (ICadDrawingWorkspace)pWorkspace;
           //Open the CadDrawingDataset 
            ICadDrawingDataset   pCadDwgDataset;
            pCadDwgDataset = pCadDwgWorkspace.OpenCadDrawingDataset("15413422.DWG");

            //在Mapcontrol中打开ＣＡＤ图形
            if (pCadDwgDataset == null) return;
            ICadLayer  pCadLayer = new CadLayerClass();
            pCadLayer.CadDrawingDataset = pCadDwgDataset;
           
            this.axMapControl1.AddLayer(pCadLayer, 0);

       
       
        }