我有一個(gè) DropDownList，其中填充了 SQL 表中的數(shù)據(jù)。在網(wǎng)絡(luò)表單中，當(dāng)用戶從該列表中選擇一個(gè)項(xiàng)目時(shí)，我希望它將所選選項(xiàng)插入到另一個(gè) SQL 表中，除了 DropDownLists 之外的所有內(nèi)容都有效我試過(guò)了 ：cmd.Parameters.AddWithValue("@*", ddl*.SelectedValue);cmd.Parameters.AddWithValue("@*", ddl*.SelectedItem.Text);ETCusing System;using System.Collections.Generic;using System.Linq;using System.Web;using System.Web.UI;using System.Web.UI.WebControls;using System.Data.SqlClient;using System.Windows.Forms;using System.Data;using System.Configuration;using System.Text;using System.Drawing;namespace VXUK2{    public partial class booking_system : System.Web.UI.Page    {        protected void Page_Load(object sender, EventArgs e)        {            // SQL Query For DropDownList1 (CIT Company)                SqlConnection con = new SqlConnection();                con.ConnectionString = ("Data Source=(LocalDB)\\MSSQLLocalDB;AttachDbFilename=C:\\****;Persist Security Info=True;User ID=***;Password=****;Connect Timeout=30");                con.Open();                SqlCommand cmd = new SqlCommand("Select CIT_ID, CIT_CompanyName from CIT_Details", con);                ddlCITCompany.DataSource = cmd.ExecuteReader();                ddlCITCompany.DataTextField = "CIT_CompanyName";                ddlCITCompany.DataValueField = "CIT_ID";                ddlCITCompany.DataBind();            // SQL Query for DropDownList2 (Site Details)                SqlConnection con2 = new SqlConnection();                con2.ConnectionString = ("Data Source=(LocalDB)\\MSSQLLocalDB;AttachDbFilename=C:\\***;Persist Security Info=True;User ID=***;Password=****;Connect Timeout=30");                con2.Open();                SqlCommand cmd2 = new SqlCommand("Select Site_ID, Site_Name from Site_Details", con2);                ddlVisitingCentre.DataSource = cmd2.ExecuteReader();                ddlVisitingCentre.DataTextField = "Site_Name";                ddlVisitingCentre.DataValueField = "Site_ID";                ddlVisitingCentre.DataBind();        }