asp.net DropDownList 三级联动下拉菜单

最新推荐文章于 2025-05-15 15:12:24 发布

转载最新推荐文章于 2025-05-15 15:12:24 发布 · 147 阅读

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原文链接：http://www.cnblogs.com/juan/archive/2009/04/11/1433698.html

本文介绍了一个使用 ASP.NET 实现的分类选择功能，包括一级、二级和三级分类的下拉框联动效果。通过数据库查询填充下拉框，并在用户选择不同级别的分类时动态更新子级分类选项。

if (!IsPostBack)
        {
            //一级分类列表
            this.DropDownList1.DataSource = dsbb.SelectSubjct1();
            this.DropDownList1.DataTextField = "cName";
            this.DropDownList1.DataValueField = "Ccode";
            this.DropDownList1.DataBind();

            this.DropDownList1.Items.Insert(0,new ListItem("请选择一级分类","0"));
            this.DropDownList8.Items.Insert(0, new ListItem("请选择二级分类", "0"));
            this.DropDownList9.Items.Insert(0,new ListItem ("请选择三级分类","0"));

//二级分类列表

}

/// <summary>
    /// 绑定二级分类
    /// </summary>
    /// <param name="sender"></param>
    /// <param name="e"></param>
    protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
    {
        libs.Database.Dbbase dbb = new libs.Database.Dbbase();
        if (Convert.ToInt32(this.DropDownList1.SelectedValue) == 0) //清除列表内容
        {
            this.DropDownList8.Items.Clear();
            this.DropDownList8.Items.Insert(0, new ListItem("请选择二级分类", "0"));
            this.DropDownList9.Items.Clear();
            this.DropDownList9.Items.Insert(0, new ListItem("请选择三级分类", "0"));

        }
        else //二级分类列表
        {
            this.DropDownList8.DataSource = dbb.Selectsubjct2(this.DropDownList1.SelectedValue.Substring(0,2));
            this.DropDownList8.DataTextField = "cName";
            this.DropDownList8.DataValueField = "Ccode";
            this.DropDownList8.DataBind();
            this.DropDownList8.Items.Insert(0,new ListItem ("请选择二级分类","0"));

            this.DropDownList9.Items.Clear();//清除第三分类
            this.DropDownList9.Items.Insert(0, new ListItem("请选择三级分类", "0"));
        }

    }
    /// <summary>
    /// 绑定三级分类
    /// </summary>
    /// <param name="sender"></param>
    /// <param name="e"></param>
    protected void DropDownList8_SelectedIndexChanged(object sender, EventArgs e)
    {
        libs.Database.Dbbase dbase = new libs.Database.Dbbase();
        this.DropDownList9.DataSource = dbase.selectsubject3(this.DropDownList8.SelectedValue.Substring(0,4));
        this.DropDownList9.DataTextField = "cName";
        this.DropDownList9.DataValueField = "Ccode";
        this.DropDownList9.DataBind();
        this.DropDownList9.Items.Insert(0,new ListItem("请选择三级分类","0"));
    }

Dbbase.cs页：

/// <summary>
       /// 查询一级栏目
       /// </summary>
       /// <returns></returns>
       public DataSet SelectSubjct1()
       {
           string con = System.Configuration.ConfigurationSettings.AppSettings["sqlconn"];
           SqlConnection conn = new SqlConnection(con);
           string sqlstr = "SELECT kndid, Ccode, cName, cLevel FROM kind WHERE cLevel = 1";
           DataSet dst = new DataSet();
           SqlDataAdapter sda = new SqlDataAdapter(sqlstr,conn);
           try
           {
               sda.Fill(dst);
               return dst;
           }

转载于:https://www.cnblogs.com/juan/archive/2009/04/11/1433698.html