从SQL数据库中使用String选择DropDownList值

Question

I can't get my code below to set my DropDownList to the correct value.

Its the code in the else statement that is not working for me but its not throwing any exceptions either.

The DropDownList is being set from one database where I store program information. The database I'm accessing with reader1 is a user information database which has the string value selected on registration from the DropDownList, so I cant use the index. Could someone please point out where I'm going wrong?

I just want to retrieve my text string from the user database, populate the DropDownList from the program database, then have the database show the item that matches the string. Its this last part, auto selecting the item, thats the problem.

private DataTable loadAdBusinessTypes1()
        {
            string prgInfoConnection = ConfigurationManager.ConnectionStrings["program_infoConnection"].ToString();
            SqlConnection oSqlConnection = new SqlConnection(prgInfoConnection);
            SqlCommand oSqlCommand = new SqlCommand();
            oSqlCommand.Connection = oSqlConnection;
            oSqlCommand.CommandType = CommandType.StoredProcedure;
            oSqlCommand.CommandText = "pGetAdBusinessTypes";
            SqlDataAdapter oSqlDataAdapter = new SqlDataAdapter();
            oSqlDataAdapter.SelectCommand = oSqlCommand;
            DataTable oDataTable1 = new DataTable("AdBusinessTypes");
            oSqlDataAdapter.Fill(oDataTable1);
            return oDataTable1;
        }

        protected void Page_Load(object sender, EventArgs e)
        {
            if (Session["New"] == null)
            {
                Response.Redirect("~/Account/Login.aspx"); //*****CHANGE REDIRECT WEBPAGE*****
            }
            else
            {
                if (!Page.IsPostBack)
                {
                    DataTable oDataTable = loadAdBusinessTypes1();
                    BusTypeddl.DataSource = oDataTable;
                    BusTypeddl.DataTextField = "business_type";
                    BusTypeddl.DataBind();
                }

                try
                {
                    if (Session["New"] == null)
                    {
                        Response.Redirect("~/Account/Login.aspx"); //*****CHANGE REDIRECT WEBPAGE*****
                    }
    else
                        {

                            string str = Convert.ToString(Session["New"]);
                            string cmdText = @"select account_no, first_name, last_name, email_1, email_2, business_street_1, business_street_2, business_street_3, business_city, business_state, business_postal_code, business_country, company_name, business_type, phone_1, phone_2, phonecode_1, phonecode_2, website, registration_date, screens_no, user_password from users where email_1 =@email";
                            string cpUsersConnection = ConfigurationManager.ConnectionStrings["cp_usersConnection"].ToString();
                            using (SqlConnection oSqlConnection = new SqlConnection(cpUsersConnection))
                            using (SqlCommand oSqlCommand = new SqlCommand(cmdText, oSqlConnection))
                            {
                                oSqlConnection.Open();
                                oSqlCommand.Parameters.Add("@email", SqlDbType.NVarChar).Value = str;
                                using (SqlDataReader reader1 = oSqlCommand.ExecuteReader())
                                {
                                    if (reader1.Read())
                                    {

                                        var findBusType = reader1["business_type"].ToString().Trim();
                                        var selectedIndex = -1;

                                        for (int i = 0; i < BusTypeddl.Items.Count; i++)
                                        {
                                            if (BusTypeddl.Items[i].ToString() == findBusType)
                                            {
                                                selectedIndex = i;
                                                break;
                                            }
                                        }
                                        if (selectedIndex > -1)
                                        {
                                            BusTypeddl.SelectedIndex = selectedIndex;
                                        }

                                    }
                                }
                            }
                        }

Answer 1

Try to change your first method to:

private DataTable loadAdBusinessTypes1()
    {
        string prgInfoConnection = ConfigurationManager.ConnectionStrings["program_infoConnection"].ToString();
        SqlConnection oSqlConnection = new SqlConnection(prgInfoConnection);
        SqlCommand oSqlCommand = new SqlCommand("pGetAdBusinessTypes", oSqlConnection);
        oSqlCommand.CommandType = CommandType.StoredProcedure;
        DataTable dt = new DataTable();
        try{
            oSqlConnection.Open();
            SqlDataAdapter oSqlDataAdapter = new SqlDataAdapter(oSqlCommand);
            DataTable oDataTable1 = new DataTable("AdBusinessTypes");
            oSqlDataAdapter.Fill(oDataTable1);
            dt = oDataTable1;
        }
        catch(Exception ex){
            //you may work with exceptions here
        }
        finally{
            oSqlConnection.Close();
        }
        return dt;
    }