Hai perso il connectionString
Se vuoi popolare l'elenco da DB ci sono molti modi
Con DataReader
Imports System.Data.Sql
Imports System.Data.SqlClient
Public Class Form1
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
Dim connectionString As String = "Data Sourec=localhost;........."
Dim conn As New SqlConnection(connectionString)
conn.Open()
Dim comm As New SqlCommand("SELECT name FROM Table_1", conn)
Dim reader As SqlDataReader = comm.ExecuteReader
/* As it is not working i commented this
listBox1.ItemsSource = dt; // use this instead of ListBox1.Items.Add(dt)
//because Add event add only one item in the list.
*/
Dim i As Integer
i=0
while reader.read()
listbox1.Items.Add(dr(i).ToString);
i++
End While
End Sub
End Class
Con DataTable
Imports System.Data.Sql
Imports System.Data.SqlClient
Public Class Form1
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
Dim connectionString As String = "Data Sourec=localhost;........."
Dim conn As New SqlConnection(connectionString)
conn.Open()
// Create new DataAdapter
SqlDataAdapter a = new SqlDataAdapter("SELECT * FROM EmployeeIDs", c)
// Use DataAdapter to fill DataTable
DataTable dt = new DataTable();
a.Fill(dt);
ListBox1.DataSource = dt;
ListBox1.DataTextField = "name";
End Sub
End Class
MODIFICA:
Gli altri parametri della stringa di connessione dipendono dalla tua sicurezza e tutto il resto. Devi vedere questo link Stringhe di connessione per SQL Server 2008
