public static ExamFileService GetInstance()
{
if (instance == null)
{
instance = new ExamFileService();
}
return(instance);
}
public bool Save(Exam exam)
{
try
{
password = exam.Password;
SaverName = exam.Name;
ExamFileService fileService = ExamFileService.GetInstance();
fileService.SaveExam(exam, filePath);
openedExam = exam;
return(true);
}
catch (Exception ex)
{
LastExceptionMessage = ex.Message;
return(false);
}
}
public bool SaveResult(ExecutionResult executionResults)
{
Exam exam = GetExam();
if (exam is null)
{
return(false);
}
exam.ExecutionResults.Add(executionResults);
try
{
password = exam.Password;
SaverName = exam.Name;
ExamFileService fileService = ExamFileService.GetInstance();
fileService.SaveExam(exam, filePath);
return(true);
}
catch (Exception ex)
{
LastExceptionMessage = ex.Message;
return(false);
}
}
public Exam GetExam()
{
if (openedExam != null)
{
return(openedExam);
}
Exam exam;
try
{
ExamFileService fileService = ExamFileService.GetInstance();
exam = fileService.OpenExam(filePath, password);
password = exam.Password;
SaverName = exam.Name;
}
catch (Exception ex)
{
LastExceptionMessage = ex.Message;
exam = null;
}
openedExam = exam;
return(exam);
}
public IList <Question> GetQuestions()
{
List <Question> result;
if (openedExam != null)
{
result = new List <Question>();
for (int i = 0; i < openedExam.Tickets.Count; i++)
{
result.AddRange(openedExam.Tickets[i].GetQuestions());
}
return(result);
}
Exam exam;
try
{
result = new List <Question>();
ExamFileService fileService = ExamFileService.GetInstance();
exam = fileService.OpenExam(filePath, password);
password = exam.Password;
SaverName = exam.Name;
openedExam = exam;
for (int i = 0; i < openedExam.Tickets.Count; i++)
{
result.AddRange(openedExam.Tickets[i].GetQuestions());
}
}
catch (Exception ex)
{
LastExceptionMessage = ex.Message;
result = null;
exam = null;
}
openedExam = exam;
return(result);
}