根据块名删除块和根据块名删除块引用 的区别

** 删除块后,块引用如果有那么依然存在,打开文件时会报错
** 删除块引用后块一定存在
 最好的办法是先全部删除块引用,然后再删除块,这样在打开图纸时才不会报错
 以下是写好的现成的两个方法

//根据块名删除块引用
        internal static void DeleteBlockRefByBlockName(Database db, string strBlockName, string strBlockName1)
        {
            Transaction tr = db.TransactionManager.StartTransaction();
            using (tr)
            {
                BlockTable bt = tr.GetObject(db.BlockTableId, OpenMode.ForWrite) as BlockTable;
                BlockTableRecord btr = (BlockTableRecord)tr.GetObject(bt[BlockTableRecord.ModelSpace], OpenMode.ForWrite);
                foreach (ObjectId objId in btr)
                {
                    DBObject dbObj = tr.GetObject(objId, OpenMode.ForWrite);
                    if (dbObj is BlockReference )
                    {
                        BlockReference refEnt=dbObj as BlockReference ;
                        BlockTableRecord mtbtr = (BlockTableRecord)tr.GetObject(refEnt.BlockTableRecord , OpenMode.ForWrite);
                        if (mtbtr.Name.Equals(strBlockName) || (mtbtr.Name.Equals(strBlockName1)))
                        {
                            refEnt.Erase();
                        }
                    }
                }
                tr.Commit();
            }
        }

 

        //根据块名删除块
        internal static void DeleteBlockByBlockName(Database db,string strBlockName, string strBlockName1)
        {
            Transaction tr = db.TransactionManager.StartTransaction();
            using (tr)
            {
                BlockTable bt = tr.GetObject(db.BlockTableId, OpenMode.ForWrite) as BlockTable;
                foreach (ObjectId objId in bt)
                {
                    BlockTableRecord bbtr = tr.GetObject(objId, OpenMode.ForWrite) as BlockTableRecord;
                    if (bbtr.Name.Equals(strBlockName) || (bbtr.Name.Equals(strBlockName1)))
                    {
                        bbtr.Erase();
                    }
                }
                tr.Commit();
            }
        }