var blkRec = ent.BlockTableRecord;
               // 创建一个用于遍历器
               var iter = blkRec.NewIterator();
               for (; !iter.Done(); iter.Step(true, false)) {
                  var tmpEnt = iter.GetEntity();
                  if (tmpEnt.ObjectName == "McDbText") {
                     // 修改文字内容
                     var sTxt = tmpEnt.TextString;
                     tmpEnt.TextString = sTxt.replace(sTxt, sTxt + "-1<被修改>"); //修改内容
                  }
                  ent.AssertWriteEnabled();