/// <summary>
/// シークバーのプログレスチェンジイベント
/// </summary>
/// <param name="s">オブジェクト</param>
/// <param name="e">イベントのデータ</param>
private async void OnProgressChanged(object s, SeekBar.ProgressChangedEventArgs e)
{
var textViewAlphaValue = (TextView)FindViewById(Resource.Id.alpha_value);
textViewAlphaValue.Text = e.Progress.ToString() + " %";
var brightness = new Brightness();
var mutableBitmap = await Task.Run(() => brightness.GoImageProcessing(mBitmap, e.Progress));
var imageView = (ImageView)FindViewById(Resource.Id.image);
imageView.SetImageBitmap(mutableBitmap.Copy(Bitmap.Config.Argb8888, false));
}
