title: Save file to device with memorystream
body: <p>I was wondering if it is possible with xamarin.forms to download any type of file to the device.. de files are stored on Azure, i get a Memorystream of the file, its very important for my app. my question excists of 2 parts actually, 
  how to download de file to the device of the user?, 
  and how to show the file of Any type in a default application of the type ( like pdf reader)</p>
  
  <p>this is what i tried</p>
  
  <blockquote>
    <p>MemoryStream memoryStream = AzureDownloader.DownloadFromAzureBlobStorage(null, doc.azure_container, doc.file_path, ref filen, true);</p>
  </blockquote>
  
  <pre><code>  string documentsPath = Environment.GetFolderPath(Environment.SpecialFolder.Personal);
    string localFilename = doc.filename;
    string localPath = Path.Combine(documentsPath, localFilename);
    File.WriteAllBytes(localPath, memoryStream.ToArray()); // this is a try to save to local storage
  </code></pre>
  
  <p>any help appreciated</p>