二级联动菜单

Question

两个 DropDownList控件，是联动菜单，想让第二个DropDownList控件点击时候触发SelectedIndexChanged事件，但是没有反应，不知道怎么回事，请指教

Answer 1

这个用JS做就好了http://zxe-llh-163-com.iteye.com/blog/806029

Answer 2

代码如下，联动都OK了，就是第二个DropDownList里显示数据后，我想任点一个把TEXT取出来
 protected void Page_Load(object sender, EventArgs e)
    {           string sql = "select * from RTX_Dept";     
        SqlConnection conn = new SqlConnection(WebConfigurationManager.ConnectionStrings["ythzhConnectionString"].ConnectionString);
        SqlCommand scomm = new SqlCommand(sql, conn);
        conn.Open();
        scomm.ExecuteNonQuery();        DataTable dt = new DataTable();
        dt.Load(scomm.ExecuteReader());   
        if (!IsPostBack)  
        {
                         
            System.Data.DataView dv = dt.DefaultView;
            dv.RowFilter = "PDeptID=0";
            DropDownList1.DataSource = dv;
            DropDownList1.DataTextField = "DeptName";
            DropDownList1.DataValueField = "DeptID";
            DropDownList1.DataBind();
            System.Data.DataView dv2 = dt.DefaultView;
            dv2.RowFilter = "PDeptID=" + DropDownList1.SelectedValue;
            DropDownList2.DataSource = dv2;
            DropDownList2.DataTextField = "DeptName";
            DropDownList2.DataValueField = "PDeptID";
            DropDownList2.DataBind();          
           
        }          
    }
  
    protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
    {        string sql = "select * from RTX_Dept";
        SqlConnection conn = new SqlConnection(WebConfigurationManager.ConnectionStrings["ythzhConnectionString"].ConnectionString);
        SqlCommand scomm = new SqlCommand(sql, conn);
        conn.Open();
        scomm.ExecuteNonQuery();        DataTable dt = new DataTable();
        dt.Load(scomm.ExecuteReader());
        System.Data.DataView dv2 = dt.DefaultView;
        dv2.RowFilter = "PDeptID=" + DropDownList1.SelectedValue;
        DropDownList2.DataSource = dv2;
        DropDownList2.DataTextField = "DeptName";
        DropDownList2.DataValueField = "PDeptID";
        DropDownList2.DataBind();
        Session["Temp_Name1"] = DropDownList1.SelectedItem.Text;
        string Temp_Class = "select * from IP_LocalAllot where [DeptName] = '" + Session["Temp_Name1"] + "'";
        SqlConnection con = new SqlConnection(WebConfigurationManager.ConnectionStrings["ythzhConnectionString"].ConnectionString);
        SqlCommand scom = new SqlCommand(Temp_Class, con);
        con.Open();
        scom.ExecuteNonQuery();        SqlDataReader CN;
        CN = scom.ExecuteReader();        while (CN.Read())
        {
            Label1.Text = CN["ID"].ToString();  //取出单位ID（用来赋值给PID）            
        }
        con.Close();        string T_ID = Label1.Text.Trim();   //录入数据时把T_ID赋值给数据表IP_LocalAllot里的PID
       
    }    protected void DropDownList2_SelectedIndexChanged(object sender, EventArgs e)
    {
        // 把相对应的下级单位名称赋值给数据表IP_LocalAllot里的DeptName        Label2.Text = DropDownList2.SelectedValue;
        string T_Name = Label2.Text.Trim();  
       
    }   

Answer 3

检查autopostback是否为true 

Answer 4

DropDownList2.AutoPostBack = true;

Answer 5

DropDownList2.AutoPostBack = true;
知道是这个，还是不行，不知道哪的问题