【ASP.NET 进阶】TreeView控件学习

1.效果图

2 后台数据库数据填充方式

a.数据库数据

b.前台页面

 TreeViewTest.aspx

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="TreeViewTest.aspx.cs" Inherits="Yc_TestS.TreeViewTest" %>

<!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>TreeView</title>
<script type="text/javascript">
function show(msg) {
alert(msg);
}
</script>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:TreeView ID="treeT" runat="server">
</asp:TreeView>
</div>
</form>
</body>
</html>

TreeViewTest.aspx

c.后台代码

 TreeViewTest.aspx.cs

using System;
using System.Collections.Generic;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.Security;
using System.Data;
using Yc_TestS.BaseClass;

namespace Yc_TestS
{
public partial class TreeViewTest : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
AddTree(0, null);
}

private void AddTree(int Pid, TreeNode PNode)
{
string sqlStr = "SELECT Item_id,Item_name,Parent_ID FROM Para_item";
DataTable dt = YSqlHelper.ExecuteQuery(sqlStr, CommandType.Text);
if (dt.Rows.Count > 0)
{
DataView dv = new DataView(dt);
//过滤ParentID,得到当前的所有子节点 ParentID为父节点ID
dv.RowFilter = "[Parent_ID] = " + Pid;
//循环递归
foreach (DataRowView Row in dv)
{
//声明节点
TreeNode Node = new TreeNode();
//绑定超级链接
Node.NavigateUrl = String.Format("javascript:show('{0}')", Row["Item_Name"].ToString());
//开始递归
if (PNode == null)
{
//添加根节点
Node.Text = Row["Item_Name"].ToString();
treeT.Nodes.Add(Node);
Node.Expanded = true; //节点状态展开
AddTree(Int32.Parse(Row["Item_ID"].ToString()), Node); //再次递归
}
else
{
//添加当前节点的子节点
Node.Text = Row["Item_Name"].ToString();
PNode.ChildNodes.Add(Node);
Node.Expanded = true; //节点状态展开
AddTree(Int32.Parse(Row["Item_ID"].ToString()), Node); //再次递归
}
}
}
}
}
}

TreeViewTest.aspx.cs

d.配置文件

 Web.config

<?xml version="1.0"?>
<!--
有关如何配置 ASP.NET 应用程序的详细消息，请访问
http://go.microsoft.com/fwlink/?LinkId=169433
-->
<configuration>

<appSettings>
<add key="sqlStr" value="0dd8de75eb51766d66d42ead8ea26b0c533f6fdb009e9fd2e6e1c9867d2766ec499405047e4173a74015f57800e3afb982fd39d96dcc1590c8c943242992c84b "/>
</appSettings>
<system.web>
<compilation debug="true"/>
</system.web>
</configuration>

Web.config

e.两个助手类 

 加密和解密（EntryCode.cs）

using System;
using System.Collections.Generic;
using System.Web;
using System.IO;
using System.Security.Cryptography;
using System.Text;

namespace Yc_TestS.BaseClass
{
public class EntryCode
{
/// <summary>加密</summary>
public static string EncodeCode(string str)
{
string key = "david.yc";
DESCryptoServiceProvider provider = new DESCryptoServiceProvider();
provider.Key = Encoding.ASCII.GetBytes(key.Substring(0, 8));
provider.IV = Encoding.ASCII.GetBytes(key.Substring(0, 8));
byte[] bytes = Encoding.GetEncoding("GB2312").GetBytes(str);
MemoryStream stream = new MemoryStream();
CryptoStream stream2 = new CryptoStream(stream, provider.CreateEncryptor(), CryptoStreamMode.Write);
stream2.Write(bytes, 0, bytes.Length);
stream2.FlushFinalBlock();
StringBuilder builder = new StringBuilder();
foreach (byte num in stream.ToArray())
{
builder.AppendFormat("{0:X2}", num);
}
stream.Close();
return builder.ToString().Trim();
}

/// <summary> Des 解密 GB2312 </summary>
public static string DecodeCode(string str)
{
string key = "david.yc";
DESCryptoServiceProvider provider = new DESCryptoServiceProvider();
provider.Key = Encoding.ASCII.GetBytes(key.Substring(0, 8));
provider.IV = Encoding.ASCII.GetBytes(key.Substring(0, 8));
byte[] buffer = new byte[str.Length / 2];
for (int i = 0; i < (str.Length / 2); i++)
{
int num2 = Convert.ToInt32(str.Substring(i * 2, 2), 0x10);
buffer[i] = (byte)num2;
}
MemoryStream stream = new MemoryStream();
CryptoStream stream2 = new CryptoStream(stream, provider.CreateDecryptor(), CryptoStreamMode.Write);
stream2.Write(buffer, 0, buffer.Length);
stream2.FlushFinalBlock();
stream.Close();
return Encoding.GetEncoding("GB2312").GetString(stream.ToArray()).Trim();
}
}
}

加密和解密（EntryCode.cs）

 SQL数据库助手类（YSqlHelper.cs）

using System;
using System.Collections.Generic;
using System.Web;
using System.Data;
using System.Data.SqlClient;
using System.Configuration;

namespace Yc_TestS.BaseClass
{
public class YSqlHelper
{
private static string connectionString = EntryCode.DecodeCode(ConfigurationManager.AppSettings["sqlStr"]);//获取解密后的数据库连接字符串

/// <summary>执行不带参数的增删改SQL语句或存储过程</summary>
/// <param name="cmdText">增删改SQL语句或存储过程</param>
/// <param name="ct">命令类型</param>
/// <returns>受影响的行数</returns>
public static int ExecuteNonQuery(string cmdText, CommandType ct)
{
int res = 0;
using (SqlConnection conn = new SqlConnection(connectionString))
{
try
{
conn.Open();
using (SqlCommand cmd = new SqlCommand(cmdText, conn))
{
cmd.CommandType = ct;
res = cmd.ExecuteNonQuery();
}
}
catch
{

}
finally
{
if (conn.State == ConnectionState.Open)
{
conn.Close();
}
}
}
return res;
}

/// <summary>执行带参数的增删改SQL语句或存储过程</summary>
/// <param name="cmdText">增删改SQL语句或存储过程</param>
/// <param name="ct">命令类型</param>
/// <returns>受影响的行数</returns>
public static int ExecuteNonQuery(string cmdText, SqlParameter[] paras, CommandType ct)
{
int res = 0;
using (SqlConnection conn = new SqlConnection(connectionString))
{
try
{
conn.Open();
using (SqlCommand cmd = new SqlCommand(cmdText, conn))
{
cmd.CommandType = ct;
cmd.Parameters.AddRange(paras);
res = cmd.ExecuteNonQuery();
}
}
catch
{

}
finally
{
if (conn.State == ConnectionState.Open)
{
conn.Close();
}
}
}
return res;
}

/// <summary> 执行带参数的查询SQL语句或存储过程</summary>
/// <param name="cmdText">查询SQL语句或存储过程ì</param>
/// <param name="paras">参数集合?</param>
/// <param name="ct">命令类型</param>
/// <returns>DataTable对象</returns>
public static DataTable ExecuteQuery(string cmdText, CommandType ct)
{
DataTable dt = new DataTable();
using (SqlConnection conn = new SqlConnection(connectionString))
{
try
{
conn.Open();
using (SqlCommand cmd = new SqlCommand(cmdText, conn))
{
cmd.CommandType = ct;
using (SqlDataReader sdr = cmd.ExecuteReader(CommandBehavior.CloseConnection))
{
dt.Load(sdr);
}
}
}
catch
{

}
finally
{
if (conn.State == ConnectionState.Open)
{
conn.Close();
}
}
}
return dt;
}

/// <summary> 执行带参数的查询SQL语句或存储过程</summary>
/// <param name="cmdText">查询SQL语句或存储过程ì</param>
/// <param name="paras">参数集合?</param>
/// <param name="ct">命令类型</param>
/// <returns>DataTable对象</returns>
public static DataTable ExecuteQuery(string cmdText, SqlParameter[] paras, CommandType ct)
{
DataTable dt = new DataTable();
using (SqlConnection conn = new SqlConnection(connectionString))
{
try
{
conn.Open();
using (SqlCommand cmd = new SqlCommand(cmdText, conn))
{
cmd.CommandType = ct;
cmd.Parameters.AddRange(paras);
using (SqlDataReader sdr = cmd.ExecuteReader(CommandBehavior.CloseConnection))
{
dt.Load(sdr);
}
}
}
catch
{

}
finally
{
if (conn.State == ConnectionState.Open)
{
conn.Close();
}
}
}
return dt;
}

}
}

SQL数据库助手类（YSqlHelper.cs）

3.一些方法记录

a.控制父结点的开/合状态

TreeView_Tree.GetNodeFromIndex("1").Expanded=false/true;

b.清除某个父结点下的所有子节点

TreeView_IndexLeft.GetNodeFromIndex("1").Nodes.Clear();

c.设置所选节点，如选中第二个节点 

function SetSelNode()  {   TreeView_Tree.selectedNodeIndex="1";  } 

d.得到所选节点的Text，ID或NodeData 

function GetAttribute()  {   alert(TreeView_Tree.getTreeNode(TreeView_Tree.selectedNodeIndex).getAttribute("Text"));  } 

//替换Text为ID或NodeData，可分别得到所选节点的ID或NodeData 

e.修改节点属性，如修改第一个节点的Text 

function ModifyNode()  {   var node=TreeView_Tree.getTreeNode("0");   node.setAttribute("Text","第一个节点");  } 

f.添加节点 

function AddNode()  {   var node=TreeView_Tree.createTreeNode();   node.setAttribute("Text","第一个节点");   TreeView_Tree.add(node);      } 

g.TreeView 中的SelectedIndexChange不执行

AutoPostBack=true，SelectedIndexChange才能被执行。 

h.判断 TreeView 的一个节点下是否有子节点 

if(SelectNode.Nodes.Count==0) {    //该节点没有字节点  } 

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原文地址：https://www.cnblogs.com/huangtaiyu/p/5785135.html