title: Separating multiple digits numbers from numbers in Form1_KeyPress
body: <p>I am using a Keypress function to detect keypad-number-keypresses to use them later.</p>
  <p>No bigger challenge in that.</p>
  <p>Yet my goal is to also use 2 digits or more.</p>
  <p>My approach</p>
  <pre><code>private void Form1_KeyPress(object sender, KeyPressEventArgs e)
  {
      if (True)
      {
          string zahlj = e.KeyChar.ToString();
          DateTime dtj = DateTime.Now;
          if ((dtj - dtv).TotalMilliseconds &lt; 500)
              zahl += zahlj;
          else
              zahl = zahlj;
          dtv = dtj;
          this.Text = zahl;
      }
  }
  DateTime dtv = DateTime.Now;
  string zahl = &quot;&quot;;
  </code></pre>
  <p>This works, assuming a delay of 500 Milliseconds between succeeding keystrokes.</p>
  <p>The problem is that once the number was entered, a function B should be called. Now, how do I know that it's the final number?</p>
  <p>Which is the right approach, when can I call B?</p>