<asp:DropDownList数据库读取

.aspx

<asp:DropDownList ID="DropDownList1" runat="server"  DataValueField="infoID" DataTextField="Dtitle">
        <asp:ListItem>       </asp:ListItem>
     </asp:DropDownList>

.cs

读值

 if (!IsPostBack)
        {

 int id = Convert.ToInt32(Request.QueryString["infoID"]);
          
            DataAccess.Da dac = new DataAccess.Da();
            dac.con.Open();
            SqlCommand cmd = new SqlCommand("select * from table where Id = " + id + "");
            cmd.Connection = dac.con;
            SqlDataReader sdr = cmd.ExecuteReader();
            sdr.Read();
            txttitle.Text = sdr["Xtitle"].ToString();
            txtzhaiyao.Text = sdr["Abstract"].ToString();
            content1.Value = sdr["BContent"].ToString();

            DropDownList1.SelectedValue = sdr["Did"].ToString();

            getDataLei();

}

 public void getDataLei()
    {

        DataAccess.Da dac = new DataAccess.Da();
        string sql = "select * from Ency_info where Encytype=1";
        SqlCommand cmd = new SqlCommand(sql, dac.con);
        SqlDataAdapter da = new SqlDataAdapter(cmd);
        DataSet ds = new DataSet();
        da.Fill(ds);
        this.DropDownList1.DataSource = ds.Tables[0].DefaultView;
        this.DropDownList1.DataBind();
    }

入库

        string strtype = this.DropDownList1.SelectedItem.ToString();
        string strbid = this.DropDownList1.SelectedItem.Value;

//selectedItem——指的是选中的dropdownlist中选项，为ListItem，只读不写

//selectedValue——指的是选中的dropdownlist中选项的值，为string， 只读不写
//selecteditem是选中的项，它包括value和text