title: UWP app: FileOpenPicker PickSingleFileAsync() can't await
body: <p>I'm trying to let the user browse for a file with the FileOpenPicker class, but when I use the PickSingleFileAsync function with await, I get following error:</p>
  
  <blockquote>
    <p>'IAsyncOperation' does not contain a definition for 'GetAwaiter' and no extension method 'GetAwaiter' accepting a first argument of type 'IAsyncOperation' could be found (are you missing a using directive for 'System'?)</p>
  </blockquote>
  
  <p>This is the function that gives the error on it's last line:</p>
  
  <pre><code>private async void browseFileButton_Click(object sender, RoutedEventArgs e) {
      FileOpenPicker filePicker = new FileOpenPicker();
      filePicker.ViewMode = PickerViewMode.Thumbnail;
  
      selectedFile = await filePicker.PickSingleFileAsync();
  }
  </code></pre>
  
  <p>The documentation from Microsoft contains an example that uses the FileOpenPicker in the same way. Has anybody had this problem or has anybody a solution for this problem?</p>