title: How to monitor the change of a variable from another dll?
body: <p>Here is what I have not figured out:
  I want my main program to monitor a variable from another dll(thread); This variable is a <code>bool</code> flag that varies between true and false depending on the external hardware trigger. Here is what I did, but apparently it was not responding to the change of the variable:</p>
  
  <pre><code>public bool IsTriggerOn
  {
      get { return TriggerWatcherDll.IsTriggerOn; }
      set
          {
               _isTriggerOn= TriggerWatcherDll.IsTriggerOn = value;
               if (_isTriggerOn == true)
               {
                    System.Windows.Forms.MessageBox.Show("Trigger is ON!");
               }
           }
  }
  </code></pre>
  
  <p>How exactly should I do this? Thanks.</p>
  
  <p>I am using C# + WPF, and the code above is from a C# code behind a xaml; </p>