title: List from async Task in sync MainPage
body: <p>I'm really looking for the solution and can't find proper instruction.
  I have async method in RestService.cs</p>
  
  <pre><code> public async static Task&lt;List&lt;Convert&gt;&gt; CheckBTCUSDAsync()
          {
              HttpClient client = new HttpClient();
              string restUrl = 
      "https://bitbay.net/API/Public/BTCUSD/trades.json";
              HttpResponseMessage responseGet = await 
      client.GetAsync(restUrl);
              if (responseGet.IsSuccessStatusCode)
              {
                  var response = await responseGet.Content.ReadAsStringAsync();
                  List&lt;Convert&gt; currencies = Convert.FromJson(response);
                  //Debug.WriteLine(currencies[0].Date);
                  return currencies;
              }
              else
              {
                  //Debug.WriteLine("***************");
                  //Debug.WriteLine("*****FALSE*****");
                  //Debug.WriteLine("***************");
                  return null;
              }
          }
  </code></pre>
  
  <p>I want to use it in my MainPage but of course I cant use await in sync method. I found that some devs suggest putting async tasks in eg OnStart method: <a href="https://xamarinhelp.com/xamarin-forms-async-task-startup/" rel="nofollow noreferrer">https://xamarinhelp.com/xamarin-forms-async-task-startup/</a>
  I need to to Bind the returned list to picker in Xaml but of course when trying to use:</p>
  
  <pre><code>var convert = RestService.CheckBTCUSDAsync().Result;
  </code></pre>
  
  <p>It hangs the UI thread. Anyone knows what is the best/easiest way to resolve this?</p>