private void BtnNameAnswer_Click(object sender, RoutedEventArgs e)
 {
     eWAccelerate.HideAll();
     eWAccelerate.gridStudentAnswer.Visibility = Visibility.Visible;
     answerList.Sort(CompareTimeAnswer);
     for (int i = 0; i < numberOfStudent; i++)
     {
         eWAccelerate.txtBlockStudentAnswerList[i].Text = answerList[i].answer;
         eWAccelerate.txtBlockStudentNameList[i].Text   = studentList[answerList[i].studentID].Name;
         eWAccelerate.txtBlockStudentTimeList[i].Text   = Math.Round(answerList[i].time, 2).ToString();
     }
     mediaAct.Play(eWAccelerate.videoAnswer);
     eWAccelerate.StartThreadAnswer();
 }