public class student:user
{
public string banji;
public int chinese;
public void Login(user []b,int j)
{

Console.WriteLine("请输人班级：");
b[j].banji = Console.ReadLine();//报错
Console.WriteLine("请输人成绩：");
b[j].chinese = int.Parse(Console.ReadLine());//报错
}
}
} public class user
{
public string name;
public int code;
public void Login(user []a,int i)
{
Console.WriteLine("请输入用户名");
a[i].name = Console.ReadLine();
Console.WriteLine("请输人密码：");
a[i].code = int.Parse(Console.ReadLine());

    } 
        static  main()
             int i = 0,j=0,k=0;
        user[]a = new user[i+1];
      student[]b = new student[j+1];
       teacher[]c = new teacher[k+1];
        Console.WriteLine("1.注册管理者信息2注册学生信息3注册教师信息4查看管理者信息5查看学生信息6查看教师信息");
        Console.WriteLine("请选择：");
        int contral = int.Parse(Console.ReadLine());
        switch (contral)
        {
            case 1:
                {   a[i]=new user();         
                a[i] . Login( a, i);      
                    i++;
                } break;
            case 2:
                {
                    b[i] = new student(); 
                    Console.WriteLine("请输入用户名");
                    b[i].name = Console.ReadLine();
                    Console.WriteLine("请输人密码：");
                    b[i].code = int.Parse(Console.ReadLine());
                    Console.WriteLine("请输人班级：");
                    b[i].banji = Console.ReadLine();
                    Console.WriteLine("请输人成绩：");
                    b[i].chinese = int.Parse(Console.ReadLine());
                   j++;
                } break;
                                    为啥有两个报错的地方呀