title: Trouble to get simple ReactiveUI sample to work
body: <p>I just started learning ReactUI and tried to follow this sample: <a href="https://www.codeproject.com/Articles/801986/Using-ReactiveUI-for-WinForms-MVVM-Design" rel="nofollow noreferrer">https://www.codeproject.com/Articles/801986/Using-ReactiveUI-for-WinForms-MVVM-Design</a>
  I start getting frustrated because I am not able to get it to work.  This is the code inquestion (copied from the sample):</p>
  
  <pre><code>//
  // ViewModel example
  //
  namespace WinFormMVVM.ViewModels
  {
      public class HomeViewModel : ReactiveUI.ReactiveObject
      {
          string ModelString;
          public string EnteredText
          {
              get { return ModelString; }
              set { this.RaiseAndSetIfChanged( ref ModelString, value);}
          }
  
          string statusString = "";
          public string Status
          {
              get{return statusString;}
              set{this.RaiseAndSetIfChanged(ref statusString,value);}
          }
  
          public ReactiveCommand&lt;object&gt; OKCmd { get; private set; }
  
          public HomeViewModel
          {
              var OKCmdObs = this.WhenAny(vm =&gt; vm.EnteredText, 
                  s =&gt; !string.IsNullOrWhiteSpace(s.Value));
              OKCmd = ReactiveCommand.Create(OKCmdObs);           // &lt;--- Trouble starts here
              OKCmd.Subscribe(_=&gt; Status = EnteredText + " is saved.");
          }
      }
  }
  </code></pre>
  
  <p>I marked the line in question.
  Compiling this code results in this error:</p>
  
  <p><code>Error  CS1503  Argument 1: cannot convert from 'System.IObservable&lt;bool&gt;' 
  to 'System.Action'</code></p>
  
  <p>I use ReactiveUI for WinForms Version 7.4.0 (which seems to be the latest stable version)</p>
  
  <p>The ReactiveUI samples on github tell me to use <code>ReactiveCommand.CreateAsyncTask(...)</code> which is an unknown method.  It is realy frustrating...</p>
  
  <p>Can someone please explain how to get the sample to work.</p>