How to select focused element in VB.net?

Question

Visual Basic

I've only been doing VB.net for a couple of days and now I'm making a calculator.
So, I want that when you click on the button, let's say "1", in the TextBox on which the focus is, this number is entered.
Help with focus.

Answer 1

If I understand correctly, then:

'У формы ставишь свойство
KeyPreview = True

'На событие KeyUp
Private Sub Form1_KeyUp(sender As Object, e As KeyEventArgs) Handles MyBase.KeyUp
    Select Case e.KeyCode
        Case Keys.D1, Keys.NumPad1
            TextBox1.Text &= 1
        Case Keys.D2, Keys.NumPad2
            TextBox1.Text &= 2
        '...'
        Case Keys.Back
            If TextBox1.Text.Length > 0 Then TextBox1.Text = TextBox1.Text.Substring(0, TextBox1.Text.Length - 1)
    End Select
End Sub