[原创]递归读取DataTable加载TreeList控件

//如转帖请注明出处，by www.csframework.com
 private void btnRecusiveCreate_Click(object sender, EventArgs e)

        {

            //获取树数据

            DataTable dt = DataProvider.Instance.GetTable("select * from [tb_department]", "tb_department");

 

            //实例化一个加载器，用于创建树

            RecusiveCreateTreeList creator = new RecusiveCreateTreeList(treeList1, dt,this.DataRow2NodeHandler);

 

            //调用CreateTree方法

            creator.CreateTree("isid", "ParentID", "0");

 

            treeList1.ExpandAll();

        }

 

  private TreeListNode DataRow2NodeHandler(DataRow row, TreeList tree, TreeListNode parentNode)

        {

            TreeListNode node = tree.AppendNode(new object[]
              { row["DeptCode"], row["DeptName"], row["TagValue"] },parentNode);

            return node;

        }

 public delegate TreeListNode DataRow2NodeHandler(DataRow row, TreeList tree, TreeListNode parentNode);

public class RecusiveCreateTreeList
{
   private TreeList _tree;
   private DataTable _data;
   private DataRow2NodeHandler _handle;
   
   public RecusiveCreateTreeList(TreeList tree, DataTable data, DataRow2NodeHandler handle)
   {
      _data = data;
      _tree = tree;
      _handle = handle;
   }
   
   private DataRow[] GetRows(string parentFieldName, string parentValue)
   {
      string filter = string.Format("{0}={1}", parentFieldName, parentValue);
      return _data.Select(filter);
   }
   
   private bool HasSubRows(string parentFieldName, string parentValue)
   {
      return this.GetRows(parentFieldName, parentValue).Length > 0;
   }
   
   /// <summary>
   /// 生成一级菜单的树结构.
   /// </summary>
   public void CreateTree(string keyFieldName, string parentFieldName, string rootValue)
   {
      
      this._tree.Nodes.Clear();
      this._tree.BeginUpdate();
      
      //根结点记录
      DataRow[] rows = this.GetRows(parentFieldName, rootValue);
      DataRow[] childs;
      
      string pValue;//parentValue;
      string kValue;//key value
      TreeListNode root;
      
      foreach (DataRow row in rows)
      {
         pValue = row[parentFieldName].ToString();
         kValue = row[keyFieldName].ToString();
         
         root = _handle(row, _tree, null);
         
         childs = this.GetRows(parentFieldName, kValue);
         if (childs.Length > 0)
         CreateChild(childs, root, keyFieldName, parentFieldName);
      }
      this._tree.EndUpdate();
   }
   
   /// <summary>
   /// 生成子菜单的树结构
   /// </summary>
   private void CreateChild(DataRow[] childs, TreeListNode parentNode,
   string keyFieldName, string parentFieldName)
   {
      string pValue;//parentValue;
      string kValue;//key value
      TreeListNode root;
      
      foreach (DataRow row in childs)
      {
         pValue = row[parentFieldName].ToString();
         kValue = row[keyFieldName].ToString();
         
         root = _handle(row, _tree, parentNode);
         
         childs = this.GetRows(parentFieldName, kValue);
         if (childs.Length > 0)
         CreateChild(childs, root, keyFieldName, parentFieldName);
      }
   }
}