EXT 2个tree节点拖拽都是 (转)

Ext.override(Ext.tree.TreeNode, {  
     clone: function() {  
        var atts = this.attributes;  
             if(this.childrenRendered || this.loaded || !this.attributes.children) {  
    var clone = new Ext.tree.TreeNode(Ext.apply({}, atts));  
      }  
      else {  
    var newAtts = Ext.apply({}, atts);  
    newAtts.children = this.cloneUnrenderedChildren();  
    var clone = new Ext.tree.AsyncTreeNode(newAtts);  
      }  
      clone.text = this.text;  
              
      for(var i=0; i<this.childNodes.length; i++){  
    clone.appendChild(this.childNodes[i].clone());  
      }  
      return clone;  
    },  
      
    cloneUnrenderedChildren: function() {  
              
      unrenderedClone = function(n) {  
        //n.id = undefined;  
        if(n.children)   
        {  
    for(var j=0; j<n.children.length; j++) {  
       n.children[j] = unrenderedClone(n.children[j]);  
    }  
        }     
        return n;  
     };  
      
     var c = [];  
    for(var i=0; i<this.attributes.children.length; i++) {  
    c[i] = Ext.apply({}, this.attributes.children[i]);  
    c[i] = unrenderedClone(c[i]);  
    }  
    return c;  
    }  
      
}); 

Ext.override(Ext.tree.TreeNode, {
     clone: function() {
    var atts = this.attributes;
             if(this.childrenRendered || this.loaded || !this.attributes.children) {
var clone = new Ext.tree.TreeNode(Ext.apply({}, atts));
      }
      else {
var newAtts = Ext.apply({}, atts);
newAtts.children = this.cloneUnrenderedChildren();
var clone = new Ext.tree.AsyncTreeNode(newAtts);
      }
      clone.text = this.text;

      for(var i=0; i<this.childNodes.length; i++){
clone.appendChild(this.childNodes[i].clone());
      }
      return clone;
    },

    cloneUnrenderedChildren: function() {

      unrenderedClone = function(n) {
//n.id = undefined;
        if(n.children)
        {
for(var j=0; j<n.children.length; j++) {
   n.children[j] = unrenderedClone(n.children[j]);
}
        }
        return n;
     };

     var c = [];
for(var i=0; i<this.attributes.children.length; i++) {
c[i] = Ext.apply({}, this.attributes.children[i]);
c[i] = unrenderedClone(c[i]);
}
return c;
    }

});

在拖拽目标树上加监听
Js代码
'beforenodedrop': function(e)  
{//实现COPY拖拽  
    if(e.source.tree == e.target.ownerTree)  
    {  
        return true;  
    }  
    var n = e.dropNode; // the node that was dropped  
    var existNode = e.target.ownerTree.getNodeById(n.id);  
   if(e.source.tree.el != e.target.ownerTree.el&&existNode==undefined)  
   {  
                              e.dropNode = n.clone(); // assign the copy as the new dropNode  
   }  
   else 
   {  
                                return false;  
   }  
}