I tryed to create my own numeric textbox here is my code:

```
public class NumericTextBox : TextBox
{

    public NumericTextBox()
        : base()
    {
        this.Text = "0";
    }

    private void HandleKeyEvent(KeyEventArgs e)
    {
        e.Handled = true;
        if ((Keyboard.Modifiers & ModifierKeys.Alt) != 0)
        {
            return;
        }
        if (e.Key == Key.Back || e.Key == Key.Delete || e.Key == Key.Left || e.Key == Key.Right ||
            e.Key == Key.D0 || e.Key == Key.D1 || e.Key == Key.D2 || e.Key == Key.D3 || e.Key == Key.D4 || e.Key == Key.D5 || e.Key == Key.D6 ||
            e.Key == Key.D7 || e.Key == Key.D8 || e.Key == Key.D9 ||
            e.Key == Key.NumPad0 || e.Key == Key.NumPad1 || e.Key == Key.NumPad2 || e.Key == Key.NumPad3 || e.Key == Key.NumPad4 || e.Key == Key.NumPad5 || e.Key == Key.NumPad6 ||
            e.Key == Key.NumPad7 || e.Key == Key.NumPad8 || e.Key == Key.NumPad9)
        {
            e.Handled = false;
        }
        else if ((e.Key == Key.Subtract || (e.Key == Key.Unknown && e.PlatformKeyCode == 189)) && base.SelectionStart == 0 && (base.Text.Length == 0 || base.Text[0] != '-'))
        {
            e.Handled = false;
        }
    }

    protected override void OnKeyDown(KeyEventArgs e)
    {
        HandleKeyEvent(e);
        base.OnKeyDown(e);
    }

    protected override void OnKeyUp(KeyEventArgs e)
    {
        HandleKeyEvent(e);
        base.OnKeyUp(e);
    }
}

```

everything works like supposed but if you press alt and some numbers it creates the ascii symbol corresponding to the number.. is there any way to block an "alt + number combination?
it seems that alt + key just gets entered without going threw OnKeyUp or OnKeyDown...