c# - C# asp.net SQL 如何通过下拉列表向数据库添加新值？

Question

下面的代码是我的代码示例如何通过文本框连接和添加我现在想要的是如何使用下拉列表添加... 代码示例如何通过下拉列表添加有人好吗？？？

public partial class SQL_Test : System.Web.UI.Page
    {
        SqlConnection myConnection;
        DataSet dataSet;
        string sql;
        SqlDataAdapter dataAdapter;
        protected void Page_Load(object sender, EventArgs e)
        {
            myConnection = new SqlConnection("trusted_connection=yes;" + "database=DataBaseConnection;" + "connection timeout=30;");
            dataSet = new DataSet();
            sql = "SELECT Firstname,Surname FROM BasicInfo";
            dataAdapter = new SqlDataAdapter(sql, myConnection);
            //fill dataset
            dataAdapter.Fill(dataSet, "datafill");

            //bind database to gridviwe
            GridView1.DataSource = dataSet;
            GridView1.DataBind();
        }
        protected void Button1_Click(object sender, EventArgs e)
        {
            myConnection.Open();
            SqlCommand AddCommand = new SqlCommand("INSERT INTO BasicInfo (Firstname,Surname) values(@a,@b)", myConnection);

            if (TextBox1.Text != null && TextBox2.Text != null)
            {
                //TextBox set Parameters
                AddCommand.Parameters.AddWithValue("@a", TextBox1.Text);
                AddCommand.Parameters.AddWithValue("@b", TextBox2.Text);

                //Execute Query
                AddCommand.ExecuteNonQuery();

                //emptied textbox's
                TextBox1.Text = "";
                TextBox1.Text = "";

                //Redirect
                Response.Redirect("SQL-Test.aspx");
            }

            //close connection
            myConnection.Close();
        }

Answer 1

要从下拉列表中获取所选值，您可以访问 Text 属性。

AddCommand.Parameters.AddWithValue("@a", TextBox1.Text);
AddCommand.Parameters.AddWithValue("@d", DropDownList1.Text);

Answer 2

您是否尝试将下拉列表的选定值传递给 sql 命令？如果是这样，您可以使用 AddCommand.Parameters.AddWithValue("@a", Dropdownlist.SelectedValue); 或 AddCommand.Parameters.AddWithValue("@a", Dropdownlist.SelectedText);