我开始学习C#，我试着创建一个类，我看了一个视频，我做了完全相同的事情。
但我不明白为什么我会得到这个错误“学生。学生（字符串，整型，双精度）'是不可访问的，由于其保护级别。”

static void Main(string[] args)
        {
            Student Student1 =  new Student("Aya", 00001, 4.0);
            Console.WriteLine(Student1.getName());
            Student1.setGPA(3.5);
            Console.WriteLine(Student1.getGPA());
        }
    }
    public class Student
    {
        private String Name;
        private int StudentId;
        private double GPA;
        private Student(String Name, int StudentId, double GPA)
        {
            this.Name = Name;
            this.StudentId = StudentId;
            this.GPA = GPA;
        }
        public String getName()
        {
            return this.Name;
        }
        public int getStudentId()
        {
            return this.StudentId;
        }
        public double getGPA()
        {
            return this.GPA;
        }
        public void setGPA(double GPA)
        {
            this.GPA = GPA;
        }
    }
}