Erlaube nur die Zahlen in PasswordBox in WPF

Question

Ich möchte geben nur Zahlen und erlaubt keine Nicht-Nummern, bitte helfen Sie mir damit.

dieser Kodex in TextBox Aber es funktioniert nicht mit PasswordBox

 Dim textBox As TextBox = TryCast(sender, TextBox) 
     Dim selectionStart As Int32 = textBox.SelectionStart 
     Dim selectionLength As Int32 = textBox.SelectionLength 
     Dim newText As [String] = [String].Empty 
     Dim count As Integer = 0 
     For Each c As [Char] In textBox.Text.ToCharArray() 
      If [Char].IsDigit(c) OrElse [Char].IsControl(c) Then 
       newText += c 
      End If 
     Next 
     textBox.Text = newText 
     textBox.SelectionStart = If(selectionStart <= textBox.Text.Length, selectionStart, textBox.Text.Length) 

danke

Answer 1

Private Sub PbPhone_PreviewTextInput(sender As Object, e As TextCompositionEventArgs) Handles PbPhone.PreviewTextInput 
    Dim regex As New Regex("[0-9]+") 
    If Not regex.IsMatch(e.Text) Then 
     e.Handled = True 
    End If 
End Sub