title: Delay timer for KeyDown event
body: <p>I have a <code>Textbox</code> that has a <code>KeyDown</code> event. This Event is bound with an event handler in the ViewModel. Below is the sample code:</p>
  
  <pre><code>&lt;TextBox x:Name="textBox" Text="{Binding TextBoxText, UpdateSourceTrigger=PropertyChanged}"&gt;
      &lt;i:Interaction.Triggers&gt;
          &lt;i:EventTrigger EventName="KeyDown"&gt;
              &lt;cmd:EventToCommand Command="{Binding Path=TextBoxKeyDownEvent}" PassEventArgsToCommand="True" /&gt;
          &lt;/i:EventTrigger&gt;
      &lt;/i:Interaction.Triggers&gt;
  &lt;TextBox.InputBindings&gt;
  </code></pre>
  
  <p>It is true that as soon as the user starts writing in the texbox, the backend event handler in ViewModel is called. But I don't want to call the event handler for each KeyDown operation. I want to call the event handler when the user starts typing in the textbox and stops for at least N milliseconds. That means I need to set a delay timer for the event. Can anyone please guide me how I can achieve that in MVVM?</p>