ios - 每次在测验中加载应用程序时随机化问题

Question

每次有人运行我的应用程序时，我都试图将我的应用程序中的一组问题随机化。现在我有

-(void)Category1{

    int QuestionSelected = rand() % 100;

    switch (QuestionSelected) {
        case 0:
            QuestionText.text = [NSString stringWithFormat:@"Here is where my first question is"];
            [Answer1 setTitle:@"First multiple choice" forState:UIControlStateNormal];
            [Answer2 setTitle:@"Second multiple choice" forState:UIControlStateNormal];
            [Answer3 setTitle:@"Third multiple choice" forState:UIControlStateNormal];
            [Answer4 setTitle:@"Fourth multiple choice" forState:UIControlStateNormal];
            Answer1Correct = YES;
            CorrectAnswerDisplay.text = [NSString stringWithFormat:@"Right Answer"];
            break;
        case 1:
            QuestionText.text = [NSString stringWithFormat:@"Here is where my second question is"];
            [Answer1 setTitle:@"First multiple choice" forState:UIControlStateNormal];
            [Answer2 setTitle:@"Second multiple choice" forState:UIControlStateNormal];
            [Answer3 setTitle:@"Third multiple choice" forState:UIControlStateNormal];
            [Answer4 setTitle:@"Fourth multiple choice" forState:UIControlStateNormal];
            Answer1Correct = YES;
            CorrectAnswerDisplay.text = [NSString stringWithFormat:@"Right Answer"];
            break;

这一切都很好而且花花公子，但它只随机化了一次。所以它随机化了我在其中的所有 100 个问题，但是如果我关闭我的应用程序并从头开始再次运行它，它会以与之前相同的方式随机化，因此它运行的方式与之前处理相同问题的方式完全相同。有什么比我的 rand() 行更好的吗？

Answer 1

rand 需要通过调用 srand 来播种。更好的是，将 rand 的使用替换为 arc4random 或 arc4random_uniform。它不需要播种并且可以提供更好的结果。