public MainWindow(User user) { InitializeComponent(); User = user; this.Title = "Hello " + user.Firstname + " " + user.Lastname; firstname.Text = user.Firstname; lastname.Text = user.Lastname; email.Text = user.Email; username.Text = user.Username; var nameList = TestsController.GetServiceName(); var listSize = nameList.Count; var newItem = new ListItem(); foreach (var item in nameList) { if (!string.IsNullOrWhiteSpace(item)) { newItem = new ListItem(); newItem.Text = item; newItem.Value = item; servicenameList.Items.Add(newItem); } } }