title: Detecting ctrl+v on key press
body: <p>I am using text box <code>keypress</code> event to handle only selected inputs. Basically the <code>textbox</code> allow user to input values where it can be calculated.</p>
  
  <p>i.e. you can type <code>(5*5)- (10/5)</code>.</p>
  
  <p>The current method check like <code>Convert.ToChar("*")==e.KeyChar</code> etc...</p>
  
  <p>At the moment it doesn't allow user to copy paste values. </p>
  
  <p>Is there anyway that can detect the <code>ctrl+v</code> on <code>keypress</code> event?</p>
  
  <p><strong>Update</strong></p>
  
  <p>What I am doing at the moment</p>
  
  <pre><code>   static IEnumerable&lt;char&gt; ValidFiancialCharacters
         {
             get
             {
                 if(_validFiancialCharacters==null)
                 {
                   _validFiancialCharacters = new List&lt;char&gt;();
  
                   _validFiancialCharacters.Add(Convert.ToChar("0"));
                   _validFiancialCharacters.Add(Convert.ToChar("1"));
                   _validFiancialCharacters.Add(Convert.ToChar("2"));
                   // till 9 and
                    _validFiancialCharacters.Add(Convert.ToChar("+"));
                    _validFiancialCharacters.Add(Convert.ToChar("-"));
                    _validFiancialCharacters.Add(Convert.ToChar("/"));
                    //and some other
                  }
                  return _validFiancialCharacters;
               }
         }
  
  
   public static bool ValidateInput(KeyPressEventArgs e)
     {
         if (ValidFiancialCharacters.Any(chr =&gt; chr == e.KeyChar))
         {
             e.Handled = false;
         }
         else
         {
             e.Handled = true;
         }
         return e.Handled;
     }
  </code></pre>
  
  <p>And in the keypress</p>
  
  <pre><code>   private void txtRate_KeyPress(object sender, KeyPressEventArgs e)
      {
          NumberExtension.ValidateInput(e);
      }        
  </code></pre>