title: In C#, how can I know the value I keyed in NumericUpDown been changed cause it out of boundary?
body: <p>I use a pair of NumericUpDowns in my program: num_Max and num_Min.
  And use Validating change boundary of them.</p>
  
  <pre><code>private void num_Validating(object sender, CancelEventArgs e){
      if((sender as NumericUpDown) == num_min)
  num_max.Minimum = num_min.Value;
  if((sender as NumericUpDown) == num_max)
  num_min.Maximum = num_max.Value;
  }
  </code></pre>
  
  <p>I want to show message "Value has been changed cause out of range!" when num_max.Minimum = 10 and user input 7. How can I do it?</p>