树TreeView控件与DataTable交互添加节点（最高效的方法）

方法一：

本文转载：http://dengzebo.blog.163.com/blog/static/18867406201032141742168/


#region "读取树结点从Datatable"

        /// <summary>

        /// 读取树结点从Datatable"

        /// </summary>

        /// <param name="TreeView1">在填充的TreeView控件</param>

        /// <param name="DT">数据源DataTable</param>

        /// <param name="IsAppendNode">是在现有TreeView控件上添加结点，还是清空再添加</param>

        /// <param name="ParentNumberColumnIndex">在DataTable中，代表父节点编号的列索引</param>

        /// <param name="NumberColumnIndex">在DataTable中，代表当前节点编号的列索引</param>

        /// <param name="NameColumnIndex">在DataTable中，代表当前节点名称的列索引</param>

        /// <returns>True/False</returns>

        public bool ReadNodesFromDataTable(TreeView TreeView1, DataTable DT, bool IsAppendNode, int ParentNumberColumnIndex, int NumberColumnIndex, int NameColumnIndex)

        {

            try

            {

                if (IsAppendNode == false)

                {

                    TreeView1.Nodes.Clear();

                }

                if (DT != null && DT.Rows.Count > 0)

                {

                    DataRow[] DR = null;

                    DR = DT.Select(DT.Columns[ParentNumberColumnIndex].ColumnName + "='' or " + DT.Columns[ParentNumberColumnIndex].ColumnName + "='0' or " + DT.Columns[ParentNumberColumnIndex].ColumnName + " is null");//先将顶级的查出来
                    for (int I = 0; I <= DR.Length - 1; I++)//先将顶级的加入到TreeView中
                    {

                        TreeNode TNode = new TreeNode(DR[I][DT.Columns[NameColumnIndex].ColumnName].ToString());

                        TNode.Tag = DR[I][DT.Columns[NumberColumnIndex].ColumnName].ToString();

                        TNode.Name = DR[I][DT.Columns[NameColumnIndex].ColumnName].ToString();

                        TreeView1.Nodes.Add(TNode);

                    }

                    for (int I = 0; I <= TreeView1.Nodes.Count - 1; I++)//再递归遍历结点
                    {

                        ForTreeNodeFormDT(TreeView1.Nodes[I], DT, ParentNumberColumnIndex, NumberColumnIndex, NameColumnIndex);

                    }

                }

                return false;

            }

            catch

            {

                return true;

            }

        }

 

        /// <summary>

        /// 从DT中递归遍历出结点
        /// </summary>

        /// <param name="TempNode">传入的顶级结点</param>

        /// <param name="DT">保存TreeView结构的DataTable</param>

        /// <param name="ParentNumberColumnIndex">在DataTable中，代表父节点编号的列索引</param>

        /// <param name="NumberColumnIndex">在DataTable中，代表当前节点编号的列索引</param>

        /// <param name="NameColumnIndex">在DataTable中，代表当前节点名称的列索引</param>

        private void ForTreeNodeFormDT(TreeNode TempNode, DataTable DT, int ParentNumberColumnIndex, int NumberColumnIndex, int NameColumnIndex)

        {

            string TTag = null;

            TTag = TempNode.Tag.ToString();

            DataRow[] DR = null;

            DR = DT.Select(DT.Columns[ParentNumberColumnIndex].ColumnName + "='" + TTag + "'");

 

            for (int I = 0; I <= DR.Length - 1; I++)

            {

                TreeNode TNode = new TreeNode(DR[I][DT.Columns[NameColumnIndex].ColumnName].ToString());

                TNode.Tag = DR[I][DT.Columns[NumberColumnIndex].ColumnName].ToString();

                TNode.Name = DR[I][DT.Columns[NameColumnIndex].ColumnName].ToString();

                TempNode.Nodes.Add(TNode);

            }

 

            foreach (TreeNode aNode in TempNode.Nodes)

            {

                ForTreeNodeFormDT(aNode, DT, ParentNumberColumnIndex, NumberColumnIndex, NameColumnIndex);

            }

        }

        #endregion

 

方法二：

做分类 经常会用到无限级别的分类  先介绍一下数据库的表结构

tid  类别编号

tname 类别名称

pid 父类编号

测试数据就不写了，大家可以自己插入一下试试

查询制定类别的 所有的子类   sql 的 代码

alter proc  proc_chaxun
(@tid int )
as
begin  

    
    with tt  as 
    (
        
        select tid,tname,pid from dbo.t_goodsType where tid=@tid
        union all
        select t.tid,t.tname,t.pid from dbo.t_goodsType  t inner join tt
        on t.pid=tt.tid
    )
    select * from tt
end 

查询之后获取记录集   绑定到前台的 TreeView 上面

 /// <summary>
            /// 给Tree 绑定数据 递归添加子节点
            /// </summary>
            /// <param name="dv">数据视图</param>
            /// <param name="tnOld">添加数据的节点</param>
            public void TreeDataBind(DataView dv,TreeNode tnOld)
            {
                TreeNode tnNew;    //创建一个新的节点
                foreach (DataRowView drv in dv)
                {
                    //为新的借点设置属性 
                    tnNew = tnOld.Nodes.Add(drv["tname"].ToString());
                    tnNew.Tag = drv["tid"];
                    //过滤数据视图 父类id = 上一级的tid
                    dv.RowFilter = "pid=" + drv["tid"].ToString();
                    //自己调用自己 
                    TreeDataBind(dv, tnNew);
                }
            }
          

调用的方法很简单

DataTable dtRet = (DataTable)dh.ExecProcRetObj(ep);
DataView dv = new DataView(dtRet);
 dv.RowFilter = "pid=0";
TreeDataBind(dv, this.treeView1.Nodes.Add("商品类别"));

效果

[知识分享] LINQ TO SQL 实现无限递归查询

本文转载：http://blog.csdn.net/q107770540/article/details/7708418

List<DetptInfo> lstDept = new List<DetptInfo> 
{
new DetptInfo {ID=1,DeptName="公司",ParentID=0},
new DetptInfo {ID=10,DeptName="软件中心",ParentID=1},
new DetptInfo {ID=11,DeptName="综合办公室",ParentID=1},
new DetptInfo {ID=100,DeptName="人力资源部",ParentID=11},
new DetptInfo {ID=101,DeptName="行政部",ParentID=11},
};



public static List<DetptInfo> GetSonID(List<DetptInfo> lstDept, int p_id)
{
var query = from c in lstDept
where c.ParentID == p_id
select c;

return query.Concat(query.SelectMany(t => GetSonID(lstDept, t.ID))).ToList();
}



--调用：

var query = GetSonID(lstDept, 0);
Console.WriteLine("Id\tName\tParent");

query.ToList().ForEach(q => Console.WriteLine("{0}\t{1}\t{2}", q.ID, q.DeptName, q.ParentID));