Question

am试图从数据库中获取选定的项目，但没有显示任何内容后面的代码：

 private void bindRows()
            {
                try
                {
                    string connectionString = ConfigurationManager.ConnectionStrings["MainConnectionString"].ConnectionString;

                    SqlConnection connection = new SqlConnection(connectionString);
                    connection.Open();



                    SqlCommand cmd = new SqlCommand("select id, message from Dropdown", connection);

                    SqlDataReader reader = cmd.ExecuteReader();

                    reader.Close();

                    SqlDataAdapter adapter = new SqlDataAdapter("select id, message from Dropdown", connection);
                    DataSet ds = new DataSet();
                    adapter.Fill(ds);

                    DdlRegister.DataSource = ds;
                    DdlRegister.DataTextField = "message";
                    DdlRegister.DataValueField = "id";
                    DdlRegister.DataBind();
                    DdlRegister.Items.Insert(0, new ListItem("I Want", "0"));
                    connection.Close();
                }
                catch (Exception e)
                {

                }
            }

按钮点击代码

 try
            {
                string connectionString = ConfigurationManager.ConnectionStrings["MainConnectionString"].ConnectionString;
                SqlConnection connection = new SqlConnection(connectionString);
                connection.Open();

                string selectCommand = "Insert into Register (name,designation,company,mobile,email,message) values(@name,@designation,@company,@mobile,@email,@message);";

                SqlCommand cmd = new SqlCommand(selectCommand, connection);
                cmd.Parameters.AddWithValue("@name", txtname.Text.Trim());
                cmd.Parameters.AddWithValue("@designation", txtdesignation.Text.Trim());
                cmd.Parameters.AddWithValue("@company", txtcompany.Text.Trim());
                cmd.Parameters.AddWithValue("@mobile", txtmobile.Text.Trim());
                cmd.Parameters.AddWithValue("@email", txtemail.Text.Trim());
                cmd.Parameters.AddWithValue("@message", DdlRegister.SelectedItem.Text.Trim());

                int cnt = cmd.ExecuteNonQuery();
                if (cnt > 0)
                {
                    ShowMessage("Registeration is done");

                }
                Response.Redirect("Index.aspx");

                connection.Close();
            }
            catch (Exception ex)
            {

            }

设计

<asp:DropDownList ID="DdlRegister" runat="server" CssClass="form-control ddl " OnSelectedIndexChanged="DdlRegister_SelectedIndexChanged" AutoPostBack="true" >
 </asp:DropDownList>

Answer 1

private void bindRows()
        {
            try
            {
                string connectionString = ConfigurationManager.ConnectionStrings["MainConnectionString"].ConnectionString;

                SqlConnection connection = new SqlConnection(connectionString);
                connection.Open();

                SqlDataAdapter adapter = new SqlDataAdapter("select id, message from Dropdown", connection);
                DataSet ds = new DataSet();
                adapter.Fill(ds);

                DdlRegister.DataSource = ds;
                DdlRegister.DataTextField = "message";
                DdlRegister.DataValueField = "id";
                DdlRegister.DataBind();
                DdlRegister.Items.Insert(0, new ListItem("I Want", "0"));
                connection.Close();
            }
            catch (Exception e)
            {

            }
        }

Answer 2

尝试类似

string mainconn = ConfigurationManager.ConnectionStrings["MY"].ConnectionString;
        SqlConnection sqlconn = new SqlConnection(mainconn);
        string sqlquery = "select * from [dbo].[sortcompany]";
        SqlCommand sqlcomm = new SqlCommand(sqlquery, sqlconn);
        sqlconn.Open();
        SqlDataAdapter sda = new SqlDataAdapter(sqlcomm);
        DataTable dt = new DataTable();
        sda.Fill(dt);
        Company.ValueMember = "company_name";
        Company.DisplayMember = "company_name";
        Company.DataSource = dt;

dropdownlist没有显示数据库中的selecteditem

2 个答案: