c# - 显示从 Class 方法返回的值到 Form

Question

在 Form GroupExmStart 中，我从 Question 类调用 Foo 方法 并将所有问题存储在 var questions 中并将其传递给 int测验方法，如何将此问题存储在string[]中，以便我可以使用DisplayQuestions()显示我的问题，我尝试使用 string[] ab=questions.ToArray(); 将其转换为字符串，但它不起作用，是无法进行转换还是哪里出错了？

形成 GroupExmStart

public partial class GroupExmStart : Form
    {        

        public GroupExmStart(string GroupName, string DurationID)
        {
            InitializeComponent();

            this.GrpID=GroupName;
            TopiID=db.GetTopicIDForGroup(GrpID);

            Question qsn = new Question();
            string[] conf = db.GetConfiguration(Convert.ToInt16(DurationID)).Split('|');
             var questions = qsn.Foo(TopiID, conf);
            int z = Quiz(questions);
            int count = 0;

            timer1.Interval = Convert.ToInt16(conf[1]) * 1000;          
             timer1.Tick += new EventHandler(timer1_Tick);
            timer1.Start();


        }

        int Quiz(List<Question> questions)
        {                   
             var str = questions.ToArray();
             foreach (var item in str)//I am not getting how do i do it Getting `item as namespaceName.Question`
                {                    
                }                
            return 0;

        }
private void DisplayQuestion(string id, string Q, string OP1, string OP2, string OP3, string OP4)
        {
            label5.Text = Q; 
            radioButton12.Text = OP4;
            radioButton11.Text = OP4;
            radioButton10.Text = OP4;           
            radioButton9.Text = OP4;
        }
      }        
   }

类问题

public class Question
    {
        public string Id { get; set; }
        public string Text { get; set; }

        public string Option1 { get; set; }
        public string Option2 { get; set; }
        public string Option3 { get; set; }
        public string Option4 { get; set; }

        public string AnswerOption { get; set; }
        public int Marks { get; set; }
        Random _random = new Random();
         public IEnumerable<Question> GetQuestions(string topicId, int marks)
        {            
            string sql = "select QID,Question,Opt1,Opt2,Opt3,Opt4,AnsOp,Marks from Questions where TopicID IN(" +
                         topicId + ") and Marks=" + marks;
            var cmd = new OleDbCommand(sql,acccon);
            var rs = cmd.ExecuteReader();

            if (rs != null)
            {
                while (rs.Read())
                {
                    yield return
                        new Question
                        {
                            Id = rs[0].ToString() + "~",
                            Text = rs[1].ToString() + "~",
                            Option1 = rs[2].ToString() + "~",
                            Option2 = rs[3].ToString() + "~",
                            Option3 = rs[4].ToString() + "~",
                            Option4 = rs[5].ToString() + "~",
                            AnswerOption = rs[6].ToString() + "~",
                            Marks = marks
                        };
                }
            }
        }

        public List<Question> Foo(string TopicId, string[] conf)
        {
            var totQsn = Convert.ToInt16(conf[0]); 
            var mark1qsn = Convert.ToInt16(conf[3]); //this variable contains number of question to be display of mark 1
            var mark2qsn = Convert.ToInt16(conf[4]);
            var mark3qsn = Convert.ToInt16(conf[5]);
            var mark4qsn = Convert.ToInt16(conf[6]);

            var mark1questionSet = GetQuestions(TopicId, 1).ToList();
            var mark2questionSet = GetQuestions(TopicId, 2).ToList();

            var finalQuestions = new List<Question>();

            for (int i = 0; i < mark1qsn; i++)
            {
                var setIndex = _random.Next(mark1questionSet.Count);
                finalQuestions.Add(mark1questionSet[setIndex]);
                mark1questionSet.RemoveAt(setIndex);
            }

            for (int i = 0; i < mark2qsn; i++)
            {
                var setIndex = _random.Next(mark2questionSet.Count);
                finalQuestions.Add(mark2questionSet[setIndex]);
                mark2questionSet.RemoveAt(setIndex);
            }

            return finalQuestions;
        }        
    } 

Answer 1

int Quiz(List<Question> questions)
{                   

    foreach (Question question in questions)
    {     
        // do something with question  
        // question.Id, question.Text etc.. can access from here             
    }                
    return 0;

}

如果你需要显示问题，你最好重写问题类的 ToString 方法，如下所示

public class Question
{

    public override string ToString()
    {
        // you can change this as you wish 
        return string.Formt("Id:{0}, Text :{1}", Id, Text);
    }

那你可以试试下面的

int Quiz(List<Question> questions)
{                   

    foreach (Question question in questions)
    {     
        MessageBox.Show(question.ToString());            
    }                
    return 0;

}

或者您可以使用下面的现有方法进行少量修改

int Quiz(List<Question> questions)
{                   
    foreach (Question question in questions)
    {     
        DisplayQuestion(question);            
    }                
    return 0;
}
private void DisplayQuestion(Question question)
{
    label5.Text = question.Text; 
    radioButton12.Text = question.Option1;
    radioButton11.Text = question.Option2;
    radioButton10.Text = question.Option3;           
    radioButton9.Text = question.Option4;
}