从数据库中获取下拉列表选择的值

Question

我有一个包含多个项目的下拉列表，并且用户保存了所有选定的值。但是当我试图从数据库中获取数据到下拉列表时。下拉列表显示的是初始值而不是数据库值。

<asp:DropDownList ID="ddimportance" Height="32" runat="server">
                                    <asp:ListItem Text="High" Value="0"></asp:ListItem>
                                    <asp:ListItem Text="Medium" Value="1"></asp:ListItem>
                                    <asp:ListItem Text="Low" Value="2"></asp:ListItem>
                                     <asp:ListItem Text="NA" Value="3"></asp:ListItem>
                                </asp:DropDownList>



using (SqlConnection con = new SqlConnection(st))
    {
        con.Open();
        SqlCommand cmd = new SqlCommand("spGetUploadedImage", con);
        cmd.CommandType = CommandType.StoredProcedure;
        cmd.Parameters.AddWithValue("@PId", Convert.ToInt32(ddproject.SelectedValue.ToString()));
        SqlDataReader rd = cmd.ExecuteReader();
        if (rd.Read())
        {
            txtuserdomain.Text = rd["P_user_domain"].ToString();
            txtawards.Text = rd["P_awards"].ToString();
            txtcoverage.Text = rd["P_functional_coverage"].ToString();
            txtfeatures.Text = rd["P_feature"].ToString();
            txtimplementation.Text = rd["P_implementation"].ToString();
            //lblimportance.Text = rd["Importance"].ToString();
            //ddimportance.ClearSelection();
            ddimportance.Items.FindByText(rd["Importance"].ToString()).Selected = true;}