ASP.NET生成树形显示的GridView实现思路

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原作者: [db:作者] 来自: [db:来源] 收藏邀请

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：

复制代码代码如下:

 
<%@ 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：

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(); 