async private void SelectLocal_Clicked(object sender, EventArgs e) { try { var result = await FilePicker.PickAsync(); if (result != null) { var stream = await result.OpenReadAsync(); var bytes = new byte[stream.Length]; await stream.ReadAsync(bytes, 0, bytes.Length); await ota.CheckUpdateLocal(bytes); } } catch (Exception ex) { // The user canceled or something went wrong } }