void CellGUI(Rect cellRect, TreeViewItem <ExcelTreeElement> item, int index, ref RowGUIArgs args)
 {
     // Center cell rect vertically (makes it easier to place controls, icons etc in the cells)
     CenterRectUsingSingleLineHeight(ref cellRect);
     if (index == 0)
     {
         args.rowRect = cellRect;
         base.RowGUI(args);
     }
     else
     {
         string value = item.data.data[index - 1];
         //选中变为不可编辑
         var selections = GetSelection();
         if (selections.Count != 0 && selections[0] == item.id)
         {
             GUI.Label(cellRect, value);
         }
         else
         {
             item.data.data[index - 1] = GUI.TextField(cellRect, value);
             //表格内容有变化,需要重新写入DataTable
             if (item.data.data[index - 1].CompareTo(value) != 0)
             {
                 m_parent.ChangeDataTable(args.row, index, item.data.data[index - 1]);
                 //item.data.data[index] = item.data.data[index - 1];
                 //m_parent.ChangeDataTable(args.row, index + 1, item.data.data[index]);
                 Debug.Log("Content Changed!!!");
             }
         }
     }
 }