Dropdownlist绑定树形数据库，Tree动态绑定数据库，动态增加节点，动态删除节点

最新推荐文章于 2018-07-31 09:57:19 发布

原创最新推荐文章于 2018-07-31 09:57:19 发布 · 2.5k 阅读

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CC 4.0 BY-SA版权

文章标签：

#数据库 #tree #string #asp #server #textbox

本文介绍了一个 ASP.NET 应用中树视图控件的实现方式，包括节点的动态添加与删除功能。重点解决了删除父节点时同步删除其子节点的问题，并提供了完整的代码示例。

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前台：

<%@ Master Language="C#" AutoEventWireup="true" CodeFile="MainMasterPage.master.cs" Inherits="Default_MainMasterPage" %>

<!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>Untitled Page</title>
</head>
<body style="margin:0">
    <form id="form1" runat="server">
    <div >
        <table style="width: 100%; height: 100%">
            <tr style="background-color:Gray">
                <td colspan="2" style="height: 80px; background-color: #cccccc;" >
                    页眉
                </td>
            </tr>
            <tr>
                <td style="width: 160px; background-color:Silver" valign="top">
                    <asp:TreeView ID="TreeLeft" runat="server" ShowLines="True">
                    </asp:TreeView>
                </td>
                <td rowspan="2">
                   <asp:ContentPlaceHolder ID="ContentPlaceHolder1" runat="server">
                    </asp:ContentPlaceHolder>
                </td>
            </tr>
            <tr>
                <td style="width: 160px; background-color: silver" valign="top">
                    Select ParentNode:<br />
                    <asp:DropDownList ID="ddlParentID" runat="server">
                    </asp:DropDownList><br />
                    Text:<asp:TextBox ID="txtNodeName" runat="server"></asp:TextBox><br />
                     <asp:Button ID="btnSubmit" runat="server" Text="Submit" OnClick="btnSubmit_Click" />
                    <asp:Button ID="btnDelete" runat="server" Text="Delete" OnClick="btnDelete_Click" /></td>
            </tr>
        </table>
       </div>
    </form>
</body>
</html>

后台：

using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Data.SqlClient;

public partial class Master_MasterPage : System.Web.UI.MasterPage
{
    protected string ConnectionString = System.Configuration.ConfigurationManager.ConnectionStrings["ConnectionString"].ToString();
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            TreeleftBind();
            bindGroup();
        }
    }
    #region 绑定树
    private void TreeleftBind()
    {
        this.TreeLeft.Nodes.Clear();
        DataTable dt = GetTable();
        DataView dv = new DataView(dt);
        dv.RowFilter = "TreeParentID = 0";
        TreeNode node = new TreeNode();
        foreach (DataRowView drv in dv)
        {
            node.Text = drv["TreeName"].ToString();
            node.Value = drv["ID"].ToString();
            node.Expanded = true;
            this.TreeLeft.Nodes.Add(node);
            AddReplies(dt, node);
        }
    }
    private void AddReplies(DataTable dt, TreeNode node)
    {

        DataView dv = new DataView(dt);

        dv.RowFilter = "TreeParentID='" + node.Value + "'";
        foreach (DataRowView row in dv)
        {
            TreeNode replyNode = new TreeNode();
            replyNode.Text = row["TreeName"].ToString();
            replyNode.Value = row["ID"].ToString();
            replyNode.NavigateUrl = row["Link"].ToString();
            replyNode.Expanded = false;
            node.ChildNodes.Add(replyNode);
            replyNode.ShowCheckBox = true;

            AddReplies(dt, replyNode);
        }

    }
    private DataTable GetTable()
    {
        SqlConnection con = new SqlConnection(ConnectionString);
        string strSQL = "select * from AutoTree";
        SqlDataAdapter da = new SqlDataAdapter(strSQL, con);
        DataTable dt = new DataTable();
        da.Fill(dt);
        return dt;
    }
    #endregion

    #region 绑定DropDownList
    private void bindGroup()
    {
        this.ddlParentID.Items.Clear();
        DataTable dt = GetTable(); //获取所有节点
        if (dt.Rows.Count > 0)
        {
            foreach (DataRow row in dt.Rows)
            {
                if (row["TreeParentID"].ToString().Trim() == "0")//绑定根节点
                {
                    this.ddlParentID.Items.Add(new ListItem(row["TreeName"].ToString(), row["Id"].ToString()));
                    this.bindDropChildItem(this.ddlParentID, dt, row["ID"].ToString(), 1);
                }
            }
        }
    }
    private void bindDropChildItem(DropDownList d, DataTable dt, string id, int length)
    {
        DataRow[] rows = dt.Select("TreeParentID='" + id + "'", "Id ASC");//取出id子节点进行绑定
        for (int i = 0; i < rows.Length; i++)
        {
            this.ddlParentID.Items.Add(new ListItem(this.SpaceLength(length) + rows[i]["TreeName"].ToString(), rows[i]["Id"].ToString()));
            this.bindDropChildItem(d, dt, rows[i]["Id"].ToString(), length + 1);//空白数目加1
        }
    }
    private string SpaceLength(int i)
    {
        string space = "";
        for (int j = 0; j < i; j++)
        {
            space += "--";
        }
        return space;
    }
    #endregion

    #region 动态增加节点
    protected void btnSubmit_Click(object sender, EventArgs e)
    {
        string rootID = ddlParentID.SelectedValue.ToString();
        string txtName = this.txtNodeName.Text;
        using (SqlConnection Conn = new SqlConnection(ConnectionString))
        {
            SqlCommand cmd = new SqlCommand("insert into AutoTree (TreeName,TreeParentID) values (@TreeName,@TreeParentID)", Conn);
            cmd.Parameters.Add("@TreeName", SqlDbType.NVarChar, 50).Value = txtName;
            cmd.Parameters.Add("@TreeParentID", SqlDbType.NVarChar, 50).Value = rootID;
            Conn.Open();
            cmd.ExecuteNonQuery();
            this.txtNodeName.Text = "";
        }
        TreeleftBind();
        bindGroup();
    }
    #endregion

    #region 动态删除节点
    protected void btnDelete_Click(object sender, EventArgs e)
    {
        if (TreeChecked() != 0)
        {
            string strjavascript = "<script language='javascript'>alert('You cant delete the node which have childnode!')</script>";
            Page.ClientScript.RegisterStartupScript(this.GetType(), "onclick", strjavascript);
        }
        else
        {
            foreach (TreeNode node in TreeLeft.CheckedNodes)
            {

                string SelectTreeID = node.Value;
                string strDelete = String.Format("delete from AutoTree where ID='{0}'", SelectTreeID);
                GetDB getDB = new GetDB();
                getDB.cmdExecute(strDelete);
            }
            TreeleftBind();
            bindGroup();
        }
    }
    protected int TreeChecked()
    {
        int count = 0;
        foreach (TreeNode node in this.TreeLeft.CheckedNodes)
        {
            if (node.ChildNodes.Count > 0)
            {
                count = count + 1;
            }
        }
        return count;
    }
    #endregion
    protected void TreeLeft_SelectedNodeChanged(object sender, EventArgs e)
    {
        TreeNode node = TreeLeft.SelectedNode;
        if (node.ChildNodes.Count != 0)
        {
            node.SelectAction = TreeNodeSelectAction.Expand;
            node.Expanded = true;
        }
        else
        {
            Response.Redirect("@" + node.NavigateUrl);//数据库中LINK字段的数据为：~/WOW/Moniqi.aspx

        }
    }
}

现在遗留的问题是：删除时如果选择了父级节点而不选该父节点下的子节点，那在提交删除后，该父节点是删除了，但是数据库里该父节点下的子节点并没有删除。现在要做的就是如何在删除父节点的同时删除该节点下的子节点。(现在加了个判断，如果节点下有子节点，将提示不能删除，至于如何选中父节点时也选中子节点，还没整出来）