大家好，
我学习C＃，现在我想通过开发一个简单的学校系统练习，我学到了什么。我遇到了很多问题，我不知道为什么。我有很多的错误，当我编译它们如:
错误11超载的'SchoolSystem.Student.setGrade（INT）"比赛方法具有一些无效参数
请帮助我。
我的代码是:
using System;
namespace SchoolSystem {
public class Student {
//Variables
string name;
string id;
double grade;
//Constructors
public Student() : this("Default Constructor") { }
public Student(string name)
{
this.Name = name;
}
public Student(string name, string id)
{
this.Name = name;
this.Id = id;
}
public Student(string name, string id, double grade) {
this.Name = name;
this.Id = id;
this.Grade = grade;
}
//Accessors
public string getName(){
return name;
}
public string getId(){
return id;
}
public int getGrade()
{
return grade;
}
//Mutators
public string setName(string newName){
name = newName;
}
public string setId(string newId){
id = newId;
}
public int setGrade(int newGrade){
grade = newGrade;
}
}
public class SchoolSystem{
public static void Main(String [] args){
Console.WriteLine("-----------------------------------");
Console.WriteLine("Welcome to Dhahran Secondary School");
Console.WriteLine("-----------------------------------");
Student s1 = new Student();
Console.WriteLine("Please enter the student name: ");
s1.setName(Console.ReadLine());
Console.WriteLine("Please enter the student id: ");
s1.setId(Console.ReadLine());
Console.WriteLine("Please enter the student grade: ");
s1.setGrade(Console.ReadLine());
Student s2 = new Student();
Console.WriteLine("Please enter the student name: ");
s2.setName(Console.ReadLine());
Console.WriteLine("Please enter the student id: ");
s2.setId(Console.ReadLine());
Console.WriteLine("Please enter the student grade: ");
s2.setGrade(Console.ReadLine());
Student s3 = new Student();
Console.WriteLine("Please enter the student name: ");
s3.setName(Console.ReadLine());
Console.WriteLine("Please enter the student id: ");
s3.setId(Console.ReadLine());
Console.WriteLine("Please enter the student grade: ");
s3.setGrade(Console.ReadLine());
Console.WriteLine("The System Information");
Console.WriteLine("The information of: {0}", s1.getName(), "\nID: ", s1.getId(), "\nGrade: ", s1.getGrade());
Console.WriteLine("The information of: {0}", s2.getName(), "\nID: ", s2.getId(), "\nGrade: ", s2.getGrade());
Console.WriteLine("The information of: {0}", s3.getName(), "\nID: ", s3.getId(), "\nGrade: ", s3.getGrade());
Console.ReadLine();
}
}
}