C# 在使用多个不同信息填充下拉列表时遇到问题

Question

I am building a form application for ordering phones. I have a drop down list which needs to have addresses of different stores. The address is stored in a MSSQL database where state,city,street and zip code are different columns in the table store. I am having trouble with getting the drop down list to show state,city,street instead of wanted data i get System.DataRowView in the drop down list as a option. I tried just requiring city or state and it works and shows the correct data.

Is there a way of getting all three informations(state,city,street) or should i just alter the sql table to contain this data in one column?

Here is the code:

            try
            {
                SqlConnection connection = getConnection();
                connection.Open();
                SqlCommand sc = new SqlCommand("select state,city,street,sotreID from store", connection);
                SqlDataReader reader;
                reader = sc.ExecuteReader();
                DataTable dt = new DataTable();
                dt.Columns.Add("street", typeof(string));
                dt.Columns.Add("storeID", typeof(int));

                dt.Load(reader);
                prodavnicaCombo.ValueMember = "storeID";
                prodavnicaCombo.DisplayMember = "state,city,street"; //the troublsome line is here
                
                prodavnicaCombo.DataSource = dt;
                connection.Close();
            }
            catch (Exception err)
            {
                MessageBox.Show("Exception: " + err.Message);
            }

Answer 1

Only one column can be used as in ValueMember & DisplayMember property. But here is wayaround you can use, instead of altering you database just concatenate your display member columns in your query and use it

 try
            {
                SqlConnection connection = getConnection();
                connection.Open();
                SqlCommand sc = new SqlCommand("select (state + ' ' city + ' ' + street) as displayMember,sotreID from store", connection);
                SqlDataReader reader;
                reader = sc.ExecuteReader();
                DataTable dt = new DataTable();
                dt.Columns.Add("street", typeof(string));
                dt.Columns.Add("storeID", typeof(int));

                dt.Load(reader);
                prodavnicaCombo.ValueMember = "storeID";
                prodavnicaCombo.DisplayMember = "displayMember"; //the troublsome line is here
                
                prodavnicaCombo.DataSource = dt;
                connection.Close();
            }
            catch (Exception err)
            {
                MessageBox.Show("Exception: " + err.Message);
            }