public void Add( BTree tree )
 {
     if( this.m_mapTree.ContainsKey(tree.m_strName))
     {
     //				Debug.LogError("The tree id is exist.");
     #if UNITY_EDITOR
         UnityEditor.EditorUtility.DisplayDialog("Error" ,"The tree named " + tree.m_strName + " is already exist.","ok");
     #endif
         return;
     }
     this.m_mapTree.Add(tree.m_strName , tree);
 }
 //load data
 public void Load(string jsontxt)
 {
     JsonData json = JsonMapper.ToObject(jsontxt);
     json = json["trees"];
     int count = json.Count;
     for(int i = 0 ; i<count ; i++)
     {
         BTree bt = new BTree();
         JsonData data = json[i];
         bt.ReadJson(data);
         this.m_mapTree.Add(bt.m_strName , bt);
     }
 }
 public void Remove(BTree tree)
 {
     if(tree == null ) return;
     if( this.m_mapTree.ContainsKey(tree.m_strName))
         this.m_mapTree.Remove(tree.m_strName);
     else
         Debug.LogError("The tree id is not exist.");
     return;
 }