关于数据邦定到DropDownList的问题请教！

在ASP.NET页面中添加两个DropDownList控件，名字为ddlist1和ddlist2，ddlist1中有产品product1,product2,product3，当选中product1后，ddlist2就会列出属于product1的条目。ddlist1和ddlist2中的数据在SQL Server中分别对应两个表，一个叫tblCatalog，另外一个叫tblItem,结构如下：tblCatalog
ID  proCatalog
1   product1
2   product2
3   product3tblItem
ID  proCatalog  Item
1   product1    item1
2   product1    item2
3   product2    item3
4   product2    item4
5   product3    item5
6   product3    item6请问如何用C#+ASP.NET+SQL Server实现，好像是个级联问题。请给个思路或者哪里有这样的实例代码。万分感谢！

解决方案 »

  1.   

    dropdownlist的selectindexchanged事件，方法自己找
      

  2.   

    private void Page_Load(object sender, System.EventArgs e)
    {
    getlist1();
    }
    private void getlist1()
    {
    SqlConnection con=new SqlConnection("server=localhost;database=userdb;uid=sa;pwd=1");
    con.Open();
    sql="select * from tblCatalog ";
    SqlDataAdapter da=new SqlDataAdapter(sql,con);
    DataSet ds=new DataSet();
    da.Fill(ds);
    ddlist1.Items.Clear();
    ddlist1.DataSource=ds;
    ddlist1.DataValueField="ID";
    ddlist1.DataTextField="proCatalog";
    ddlist1.DataBind();
    }
    private void getlist1()
    {
    SqlConnection con=new SqlConnection("server=localhost;database=userdb;uid=sa;pwd=1");
    con.Open();
    string sql="select * from tblItem where proCatalog=proCatalog='"+ddlist2.SelectedItem+"'";
    SqlDataAdapter da=new SqlDataAdapter(sql,con);
    DataSet ds=new DataSet();
    da.Fill(ds);
    ddlist2.Items.Clear();
    ddlist2.DataSource=ds;
    ddlist2.DataValueField="ID";
    ddlist2.DataTextField="proCatalog";
    ddlist2.DataBind();
    }
    private void ddlist1_SelectedIndexChanged(object sender, System.EventArgs e)
    {
    getlist();
    }
      

  3.   

    <HTML>
    <HEAD>
    <title>WebForm1</title>
    <meta content="Microsoft Visual Studio .NET 7.1" name="GENERATOR">
    <meta content="C#" name="CODE_LANGUAGE">
    <meta content="JavaScript" name="vs_defaultClientScript">
    <meta content="http://schemas.microsoft.com/intellisense/ie5" name="vs_targetSchema">
    </HEAD>
    <body MS_POSITIONING="GridLayout">
    <form id="Form1" method="post" runat="server">
    <asp:DropDownList id="ddlist1" style="Z-INDEX: 102; LEFT: 128px; POSITION: absolute; TOP: 32px" runat="server"
    AutoPostBack="True"></asp:DropDownList>
    <asp:DropDownList id="ddlist2" style="Z-INDEX: 103; LEFT: 248px; POSITION: absolute; TOP: 32px" runat="server"></asp:DropDownList></form>
    </body>
    </HTML>
      

  4.   

    要设置ddlist1的属性AutoPostBack="True"