title: Regex input only number and backspace
body: <p>I have a code </p>
  
  <pre><code>private void DataGridTypePayments_PreviewTextInput(object sender, TextCompositionEventArgs e)
          {
              e.Handled = new Regex("[^0-9]+").IsMatch(e.Text); 
          }
  </code></pre>
  
  <p>I need input number or backspace.How i can disable input symbol space?</p>