ASP.NET生成树形显示的GridView实现思路

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：

复制代码 代码如下:

using System;
using System.Data;
///

///GridViewHelper 的摘要说明
///

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
//
}
///

/// 生成树形结构的DataTable
///

/// 原始数据表
/// 上级节点关键字段
/// 上级节点值
/// 本节点关键字段
/// 显示的文本字段
/// 排序字符串
/// 处理后的DataTable
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;
}
///

/// 递归生成新的节点名称(带连接线)
///

/// 上级节点关键字段
/// 上级节点值
/// 本节点关键字段
/// 显示出来的文本字段
/// 排序字符串
/// 树深度
///
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();
}
///

/// 回溯生成树的连接线
///

/// 上级节点关键字段
/// 上级节点值
/// 本节点关键字段
/// 本节点值
/// 排序字符串
///
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：

复制代码 代码如下:

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

AutoGenerateColumns="False" BackColor="White" BorderColor="#E7E7FF" BorderStyle="None">

后台代码：

复制代码 代码如下:

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();