title: Prism Delegate command not enabling button
body: <p>I am trying to enable and disable a button in a WPF (PRISM) user control based on data entered by the user. </p>
  
  <pre><code>In the constructor I do
  SubmitCommand = new DelegateCommand&lt;object&gt;(OnSubmit, CanSubmit);
  
  
  public ICommand SubmitCommand { get; private set; }
  
  private void OnSubmit(object arg)   
  {
       _logger.Log(arg.ToString());
  }
  
  private bool CanSubmit(object arg) 
  {
      return Title.Length &gt; 0; 
  }
  
  private string _title="";
  
  public string Title
  {
  get { return _title; }
  set 
  {
      if (_title != value)
      {
             _title = value;
         this.RaisePropertyChanged();
      }
  }
  }
  </code></pre>
  
  <p>I bound the SubmitCommand in the Xaml as below </p>
  
  <pre><code>&lt;Button Content="Submit" Width="100" Command="{Binding Path=SubmitCommand}" CommandParameter="{Binding ElementName=TitleText, Path=Text}" /&gt;
  </code></pre>
  
  <p>The issue is when title value changes, the button does not get enabled. May be I am missing something. Thanks for your help! </p>