ASP.NET生成树形显示的GridView

目的：生成树形结构的表格数据（EasyUI也有TreeGrid，此处只是提供一个思路），可以扩展单击展开/收缩节点

图例：

类代码：

using System;
using System.Data;

/// <summary>
///GridViewHelper 的摘要说明
/// </summary>
public class GridViewHelper
{
    private string gridline;    //连接线
    private DataTable dt;       //传入的DataTable
    private DataTable dtOut;    //输出的DataTable
    private DataRow row;        //用于从DataView取数据并增加到dtOut
	public GridViewHelper()
	{
		//
		//TODO: 在此处添加构造函数逻辑
		//
	}
    /// <summary>
    /// 生成树形结构的DataTable
    /// </summary>
    /// <param name="datatable">原始数据表</param>
    /// <param name="parentField">上级节点关键字段</param>
    /// <param name="parentValue">上级节点值</param>
    /// <param name="keyField">本节点关键字段</param>
    /// <param name="textField">显示的文本字段</param>
    /// <param name="sortString">排序字符串</param>
    /// <returns>处理后的DataTable</returns>
	public DataTable GetGridViewTreeData(DataTable datatable, string parentField, string parentValue, string keyField, string textField, string sortString)
	{
        datatable.Columns.Add("level", Type.GetType("System.Int32"));
        dt = datatable;
        dtOut = datatable.Clone();
        resetTextField(parentField, parentValue, keyField, textField, sortString, 0);
        return dtOut;
	}
    /// <summary>
    /// 递归生成新的节点名称(带连接线)
    /// </summary>
    /// <param name="parentValueField">上级节点关键字段</param>
    /// <param name="parentValue">上级节点值</param>
    /// <param name="keyField">本节点关键字段</param>
    /// <param name="textField">显示出来的文本字段</param>
    /// <param name="sortString">排序字符串</param>
    /// <param name="level">树深度</param>
    /// <returns></returns>
    private void resetTextField(string parentValueField, string parentValue, string keyField, string textField, string sortString,int level)
    {
        DataView dv = new DataView(dt, parentValueField + "='" + parentValue + "'", sortString, DataViewRowState.CurrentRows);
        int a = dv.Count;
        if (dv.Count == 0)
        {
            return;
        }
        for (int i = 0; i < a; i++)
        {
            gridline = "";
            dv.RowFilter = parentValueField + "='" + parentValue + "'";
            dv.Sort = sortString;
            getTreeLine(parentValueField, dv[i][parentValueField].ToString(), keyField, dv[i][keyField].ToString(), sortString);
            dv.RowFilter = parentValueField + "='" + parentValue + "'";
            dv.Sort = sortString;
            row = dtOut.NewRow();
            for (int c = 0; c < dv[i].Row.ItemArray.Length; c++)
            {
                row[c] = dv[i][c];
            }
            dtOut.Rows.Add(row);
            dtOut.Rows[dtOut.Rows.Count - 1][textField] = gridline + (i == a - 1 ? "┗" : "┣") + dv[i][textField].ToString();
            dtOut.Rows[dtOut.Rows.Count - 1]["level"] = level;
            resetTextField(parentValueField, dv[i][keyField].ToString(), keyField, textField, sortString,level+1);
        }
        dv.Dispose();
    }

    /// <summary>
    /// 回溯生成树的连接线
    /// </summary>
    /// <param name="parentValueField">上级节点关键字段</param>
    /// <param name="parentValue">上级节点值</param>
    /// <param name="keyField">本节点关键字段</param>
    /// <param name="nodeKey">本节点值</param>
    /// <param name="sortString">排序字符串</param>
    /// <returns></returns>
    private void getTreeLine(string parentValueField, string parentValue, string keyField, string nodeKey, string sortString)
    {
        //选择父层节点
        DataView dv = new DataView(dt, keyField + "='" + parentValue + "'", sortString, DataViewRowState.CurrentRows);
        if (dv.Count > 0)
        {
            //选择父节点同级节点
            dv.RowFilter = parentValueField + "='" + dv[0][parentValueField].ToString() + "'";
            dv.Sort = sortString;
            for (int j = 0; j < dv.Count; j++)
            {
                if (dv[j][keyField].ToString() == parentValue)
                {
                    if (j == dv.Count - 1)
                    {
                        gridline = "　" + gridline;
                    }
                    else
                    {
                        gridline = "┃" + gridline;
                    }
                }
            }
            getTreeLine(parentValueField, dv[0][parentValueField].ToString(), keyField, dv[0][keyField].ToString(), sortString);
        }
        dv.Dispose();
    }
}

HTML示例代码：

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="GridViewTree.aspx.cs" Inherits="GridViewTree" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title>生成树形显示的GridView</title>
    <style type="text/css">
        body
        {
            line-height: 16px;
            font-size: 14px;
        }
        td
        {
            padding: 0 2px;
        }
    </style>
</head>
<body>
    <form id="form1" runat="server">
    <table>
        <tr>
            <td valign="top">
                <asp:DropDownList ID="DropDownList1" runat="server">
                </asp:DropDownList>
            </td>
            <td>
                <asp:GridView ID="GridView1" runat="server" BorderWidth="1px" CellPadding="3" GridLines="Vertical"
                    AutoGenerateColumns="False" BackColor="White" BorderColor="#E7E7FF" BorderStyle="None">
                    <AlternatingRowStyle BackColor="#F7F7F7" />
                    <Columns>
                        <asp:BoundField DataField="ConText" HeaderText="文本" />
                        <asp:BoundField DataField="id" HeaderText="ID">
                            <ItemStyle HorizontalAlign="Right" Width="80px" />
                        </asp:BoundField>
                        <asp:BoundField DataField="ParentID" HeaderText="父ID">
                            <ItemStyle HorizontalAlign="Right" Width="80px" />
                        </asp:BoundField>
                        <asp:BoundField DataField="level" HeaderText="Level">
                            <ItemStyle HorizontalAlign="Right" Width="80px" />
                        </asp:BoundField>
                    </Columns>
                    <FooterStyle BackColor="#B5C7DE" ForeColor="#4A3C8C" />
                    <HeaderStyle BackColor="#4A3C8C" Font-Bold="True" ForeColor="#F7F7F7" />
                    <PagerStyle BackColor="#E7E7FF" ForeColor="#4A3C8C" HorizontalAlign="Right" />
                    <RowStyle BackColor="#E7E7FF" ForeColor="#4A3C8C" />
                    <SelectedRowStyle BackColor="#738A9C" Font-Bold="True" ForeColor="#F7F7F7" />
                    <SortedAscendingCellStyle BackColor="#F4F4FD" />
                    <SortedAscendingHeaderStyle BackColor="#5A4C9D" />
                    <SortedDescendingCellStyle BackColor="#D8D8F0" />
                    <SortedDescendingHeaderStyle BackColor="#3E3277" />
                </asp:GridView>
            </td>
        </tr>
    </table>
    </form>
</body>
</html>

 

后台代码：

            DataTable dt = gvHelper.GetGridViewTreeData(datatable, "ParentID", "1", "ID", "ConText", "ConText asc");
            GridView1.DataSource = dt;
            GridView1.DataBind();
            DropDownList1.Items.Add("");
            DropDownList1.AppendDataBoundItems = true;
            DropDownList1.DataSource = dt;
            DropDownList1.DataTextField = "ConText";
            DropDownList1.DataValueField = "ID";
            DropDownList1.DataBind();