title: UWP . Copy file from FileOpenPicker to localstorage
body: <pre><code>FileOpenPicker picker = new FileOpenPicker();
  picker.ViewMode = PickerViewMode.Thumbnail;
  picker.SuggestedStartLocation = PickerLocationId.ComputerFolder;
  picker.FileTypeFilter.Add(".txt");
  </code></pre>
  
  <p>A user chooses a file to open. How can I store/copy/save that file to localstorage for future use, so every time the app opens, it picks automatically that file?</p>