public class Student
{
    private string _Name;
    private int _Age;
    private int _Sex;

    /// <summary>
    /// 构造函数
    /// </summary>
    public Student():this("",0,0)
    {
    }

    /// <summary>
    /// 构造函数
    /// </summary>
    /// <param name="name"></param>
    public Student(string name):this(name,10,1)
    {}

    /// <summary>
    /// 构造函数
    /// </summary>
    /// <param name="name"></param>
    /// <param name="age"></param>
    public Student(string name, int age):this(name, age, 2)
    { }

    /// <summary>
    /// 构造函数
    /// </summary>
    /// <param name="name"></param>
    /// <param name="age"></param>
    /// <param name="sex"></param>
    public Student(string name, int age, int sex)
    {
        _Name = name;
        _Age = age;
        _Sex = sex;
    }

    /// <summary>
    /// 姓名
    /// </summary>
    public string Name
    {
        get { return _Name; }
        set { _Name = value; }
    }

    /// <summary>
    /// 年龄
    /// </summary>
    public int Age
    {
        get { return _Age; }
        set { _Age = value; }
    }

    /// <summary>
    /// 性别
    /// </summary>
    public int Sex
    {
        get { return _Sex; }
        set { _Sex = value; }
    }
}

Student student1 = new Student();
Response.Write(string.Format("Name:{0},Age:{1},Sex:{2}<br/>",student1.Name,student1.Age,student1.Sex));

Student student2 = new Student("dnawo");
Response.Write(string.Format("Name:{0},Age:{1},Sex:{2}<br/>", student2.Name, student2.Age, student2.Sex));

Student student3 = new Student("dnawo", 20);
Response.Write(string.Format("Name:{0},Age:{1},Sex:{2}<br/>", student3.Name, student3.Age, student3.Sex));