DropDownList二级联动 为何子级DropDownList 显示不出来啊 求助！（已解决）

全部的代码 DropDownList二级联动

public void DataBind()
    {
        SqlConnection con = new SqlConnection(System.Configuration.ConfigurationManager.AppSettings["DNS"]);
        string Sql = "select * from dictionary where projectid like '0%'";
        SqlDataAdapter da = new SqlDataAdapter(Sql, con);
        DataSet ds = new DataSet();
        da.Fill(ds, "dictionary");
        con.Close();
        DropDownList2.DataSource = ds.Tables["dictionary"].DefaultView;
        DropDownList2.DataTextField = "name";
        DropDownList2.DataValueField = "projectid";
        DropDownList2.DataBind();
    }

 protected void DropDownList2_SelectedIndexChanged1(object sender, EventArgs e)
    {
      SqlConnection con = new SqlConnection(System.Configuration.ConfigurationManager.AppSettings["DNS"]);   
        string Sql1 = "select * from dictionary where zjid like '" + DropDownList2.SelectedValue + "%'";
        SqlDataAdapter da = new SqlDataAdapter(Sql1, con);
        DataSet ds = new DataSet();
        da.Fill(ds, "dictionary");
        con.Close();
        DropDownList3.DataSource = ds.Tables["dictionary"].DefaultView;
        DropDownList3.DataTextField = "name";
        DropDownList3.DataBind();
    }
为什么运行没效果啊，
这样的写有错吗？

[[it] 本帖最后由 lovexran 于 2008-4-15 09:54 编辑 [/it]]