Question

我只是学习C＃而无法在arraylist中显示随机对象。代码如下`

ArrayList emp = new ArrayList();

hseEmployee e3 = new hseEmployee("Aine","Porter",5,26000);
hseEmployee e4 = new hseEmployee("Tara", "Standard", 2, 20000);
hseEmployee e5 = new hseEmployee("John", "Porter", 7, 28000);
hseEmployee e6 = new hseEmployee("Keith", "Porter", 3, 22000);
hseEmployee e7 = new hseEmployee("Aine", "Porter", 5, 26000);

emp.Add(e3);
emp.Add(e4);
emp.Add(e5);
emp.Add(e6);
emp.Add(e7);

Doctor d = new Doctor("Niamh","Doctor",5,40000);
Doctor d1 = new Doctor("Briege", "Doctor", 13, 100000);
Doctor d2 = new Doctor("Thomas", "Doctor", 9, 60000);
Doctor d3 = new Doctor("Ciara", "Doctor", 1, 30000);
Doctor d4 = new Doctor("Chris", "Doctor", 6, 50000);

emp.Add(d);
emp.Add(d1);
emp.Add(d2);
emp.Add(d3);
emp.Add(d4);
for (int i = 0; i <=10; i++)
{
    Random r = new Random();
    int index = r.Next(emp.Count);
    richTextBox1.AppendText(emp[index].ToString());

}

Answer 1

将Random放在for循环之外。

随机数生成从种子值开始。如果相同种子被重复使用，生成相同的数字序列。一产生不同序列的方法是制作种子价值与时间有关，从而与每个新系列产生不同的系列随机
的实例

当你在循环中有Random时，你正在使用相同的种子值调用Random的构造函数，因此你有相同的数字，而不是随机的。

    Random r = new Random();
    for (int i = 0; i <=10; i++)
    {

        int index = r.Next(emp.Count);
        richTextBox1.AppendText(emp[index].ToString());

    }

如何在C＃中显示随机对象

1 个答案: