WPF PasswordBox validation

I'm trying to add some开发者_开发知识库 validation rules to 2 PasswordBoxes. Both must have more than 5 characters and, both passwords must match. I'm not currently using MVVM.

I figure I could check the password on the PasswordChanged event but I can't get the Invalid state to toggle on the boxes.

Does anyone have examples of something like this working?

If I'm understanding this correctly, all you need is this code within the PasswordChanged event of the second PasswordBox:

    private void passwordBox2_PasswordChanged(object sender, RoutedEventArgs e)
    {
         if (passwordBox2.Password != passwordBox1.Password)
         {
             //Execute code to alert user passwords don't match here.
             passwordBox2.Background = new SolidColorBrush(Color.FromArgb(255, 255, 0, 0));
         }
         else
         {
             /*You must make sure that whatever you do is reversed here;
              *all users will get the above "error" whilst typing in and you need to make sure
              *that it goes when they're right!*/
             passwordBox2.Background = new SolidColorBrush(Color.FromArgb(255,0,0,0));
          }
    }