Numeric TextBox in C# - WPF [duplicate]

Answer 1

For WPF:

private void textBox1_PreviewTextInput(object sender, TextCompositionEventArgs e)
{
    if (!char.IsDigit(e.Text, e.Text.Length - 1))
        e.Handled = true;
}

For Windows Forms:

private void textBox1_KeyPress(object sender, KeyPressEventArgs e)
{
    if (!char.IsDigit(e.KeyChar) )
        e.Handled = true;
}