cad.net external reference feature

What is not said, put the code

 

namespace JoinBox
{
    public enum XrefEnum
    {
        /// <summary>
        /// 卸载
        /// </summary>
        UnloadXrefs,
        /// <summary>
        /// 重载
        /// </summary>
        ReloadXrefs, 
        /// <summary>
        /// 拆离
        /// </summary>
        DetachXref,
        /// <summary>
        /// 绑定
        /// </summary>
        BindXrefs, 
    }

    public static classXrefTool 
    { 
        ///  <Summary> 
        /// modified xref
         ///  </ Summary> 
        ///  <param name = "DB"> Database </ param> 
        ///  <param name = "XE"> set enumeration status </ param> 
        ///  <param name = "names"> name of the reference to be treated with, null reference to handle all </ param> 
        public  static  void SetXref ( the this Database DB, XrefEnum XE, the IEnumerable < String > = names null ) 
        { 
            db.ResolveXrefs ( to false , to true ); // resolve external references (using linear engine,Only new) 
            var= IDS new new ObjectIdCollection ();
             var XG = db.GetHostDwgXrefGraph ( to true ); // Shenma zombie reference 
            for ( int I = 0 ; I <xg.NumNodes; I ++ ) 
            { 
                var XNode = xg.GetXrefNode (I) AS XrefGraphNode;
                 // IF (! = xNode.XrefStatus XrefStatus.Resolved) // status determination 
                IF (xNode.BlockTableRecordId.IsOk ()) 
                { 
                    IF (! names = null ) 
                    { 
                        the foreach ( var Itemin names) 
                        { 
                            // only added to the same name 
                            IF (item.ToUpper () == xNode.Name.ToUpper ()) 
                            { 
                                ids.Add (xNode.BlockTableRecordId); 
                            } 
                        } 
                    } 
                    the else 
                    { 
                        // each added 
                        ids .add (xNode.BlockTableRecordId); 
                    } 
                } 
            } 

            // btRec.IsFromOverlayReference // is covered?  
             // XrefStatus external reference status
             //GetXrefDatabase external reference database 
            IF (ids.Count == 0 ) 
            { 
                return ; 
            } 
            Switch (XE) 
            { 
                Case XrefEnum.BindXrefs: // Binds automatically detached 
                    { 
                        db.BindXrefs (IDS, to true ); 
                    } 
                    BREAK ;
                 Case XrefEnum.DetachXref: // detached 
                    {
                         the foreach (the ObjectId Item in IDS) 
                        {
                            db.DetachXref (Item);
                        } 
                    } 
                    BREAK ;
                 Case XrefEnum.UnloadXrefs: // unloading 
                    { 
                        db.UnloadXrefs (IDS);   
                    } 
                    BREAK ;
                 Case XrefEnum.ReloadXrefs: // Overload 
                    { 
                        db.ReloadXrefs (IDS); 
                    } 
                    BREAK ; 
            } 
        } 
    } 
} 

        ///  <the Summary> 
        /// the above mentioned id valid, not deleted
         ///  </ the Summary> 
        /// <param name="id"></param>
        /// <returns></returns>
        public static bool IsOk(this ObjectId id)
        {
            return !id.IsNull && id.IsValid && !id.IsErased && !id.IsEffectivelyErased && id.IsResident;
        }