Get SQL data via listbox - sql

Question

Ok, so what I am trying to do is click one item in a listbox that i have, that listbox gets data from the sql database depending on that the user types into the textbox.
Now when I click that item in the first listbox, I need more info related to that item to show up in the 2nd list box.
When the user enters a name in the textbox, the first 10 in sql show up, now that I have that, I need to click on one of the items and get the 'task' of that client in the next listbox. Task is MATTERS in the database.
I am pretty sure that my code is correct, I get no errors but nothing shows up in the list box.
Here is my code:
private void listBox1_SelectedValueChanged(object sender, EventArgs e)
{
string item = listBox1.SelectedItem.ToString();
if (listBox1.ContainsFocus)
{
if (item == "")
{
}
else
{
var con2 = Conn.ConnString();
using (SqlConnection myConnection2 = new SqlConnection(con2))
{
string oString2 = "select CLIENTMATTERS.MATTER, CLIENTMATTERS.DESCRIPTION from CLIENTMATTERS join CLIENTCODES on CLIENTMATTERS.CLIENT = CLIENTCODES.CLIENT Where CLIENTCODES.DESCRIPTION = '#code1'";
SqlCommand oCmd = new SqlCommand(oString2, myConnection2);
oCmd.Parameters.AddWithValue("#code1", item);
myConnection2.Open();
oCmd.Connection.Open();
List<string> codelist2 = new List<string>();
using (SqlDataReader oReader2 = oCmd.ExecuteReader())
{
if (oReader2.HasRows)
{
string value = string.Empty;
while (oReader2.Read())
{
codelist2.Add(oReader2["MATTER"].ToString());
}
}
}
this.listBox2.DataSource = codelist2;
}
}
}
}

Answer 1

You need to use BindingList<> instead of List<>.
The List<> doesn't implement the ListChanged event, so the ListBox doesn't get notified when the datasource changes.
In your example it would look like this:
BindingList<string> codelist2 = new BindingList<string>();
For further information take a look at
BindingList on MSDN.