Why can not select all text in textbox after focus to textbox ?

[Delaney]

By the way , there were a few other errors :

the index start at 0, not 1
when you press the down key the listbox already go to next element so when you do that

 ListBox1.SelectedIndex = ListBox1.SelectedIndex + 1

you go to the second next element..

the next element is selected after the end of the keydown event so you need

TextBox1.Text = ListBox1.Items(ListBox1.SelectedIndex + 1).ToString

instead of

TextBox1.Text = ListBox1.SelectedItem.ToString

here is a correction

    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles Me.Load
        ListBox1.Items.Add("Times New Roman")
        ListBox1.Items.Add("Arial")
        ListBox1.Items.Add("Arial Narrow")
        ListBox1.Items.Add("Monotype corsiva")
        ListBox1.Items.Add("Verdana")
        ListBox1.Items.Add("Andelip")
        ListBox1.Items.Add("Obit BT")
        ListBox1.Items.Add("LCD")
        ListBox1.Items.Add("Western")
        ListBox1.Items.Add("Roman")

        ListBox1.SelectedIndex = 0
        TextBox1.Text = ListBox1.SelectedItem.ToString

    End Sub

    Private Sub listbox_KeyDown(sender As Object, e As KeyEventArgs) Handles ListBox1.KeyDown
        If e.KeyCode = Keys.Down Then
            If ListBox1.SelectedIndex < ListBox1.Items.Count Then
                TextBox1.Text = ListBox1.Items(ListBox1.SelectedIndex + 1).ToString
            End If
        End If

        If e.KeyCode = Keys.Up Then
            If ListBox1.SelectedIndex > 0 Then
                TextBox1.Text = ListBox1.Items(ListBox1.SelectedIndex - 1).ToString
            End If
        End If
    End Sub


End Class