如何在开关盒中只进行一次？

Question

我在C#中进行测验,并随机询问我的问题.问题是我只想在每种情况下去一次.我怎样才能做到这一点？

谢谢你的回答.

Random rdmNb = new Random();
int rdm1 = rdmNb.Next(1, 11);

switch (rdm1)
{
    case 1:           
        lblQuesttion.Text = strQ1;
        break;
    case 2:
        lblQuesttion.Text = strQ2;
        break;
    case 3:
        lblQuesttion.Text = strQ3;
        break;
    case 4:
        lblQuesttion.Text = strQ4;
        break;
    case 5:
        lblQuesttion.Text = strQ5;
        break;
    case 6:
        lblQuesttion.Text = strQ6;
        break;
    case 7:
        lblQuesttion.Text = strQ7;
        break;
    case 8:
        lblQuesttion.Text = strQ8;
        break;
    case 9:
        lblQuesttion.Text = strQ9;
        break;
    case 10:
        lblQuesttion.Text = strQ10;
        break;
}

Answer 1

创建一个问题列表

List<string> questions = new List<string>()
{
   strQ1,strQ2,strQ3,strQ4,strQ5,strQ6,strQ7,strQ8,strQ9,strQ10
};

然后更改您的随机生成以从列表中查找问题

Random rdmNb = new Random();
int rdm1 = rdmNb.Next(0, questions.Count);

lblQuesttion.Text = questions[rdm1];

并从列表中删除问题

questions.RemoveAt(rdm1);

无需开关....

一定要在循环外声明Random变量,以驱动您选择下一个问题.如在这个例子中

// Declare globally the random generator, not inside the question loop
Random rdmNb = new Random();

while (questions.Count > 0)
{
    int rdm1 = rdmNb.Next(0, questions.Count);
    string curQuestion = questions[rdm1];
    questions.RemoveAt(rdm1);

    lblQuestion.Text = curQuestion;

    ... ?code to handle the user input?
}

编辑
在表单内声明并初始化具有全局范围的问题列表.

public class MyForm : Form
{
     // Declaration at global level
     List<string> questions;

     public MyForm()
     {
         InitializeComponent();
         LoadQuestions();
     }

     private void LoadQuestions()
     {
        questions = new List<string>()
        {
            strQ1,strQ2,strQ3,strQ4,strQ5,strQ6,strQ7,strQ8,strQ9,strQ10
        };

        // In future you could change this method to load your questions
        // from a file or a database.....
     }

}