隱式調用父類的構造函數

代碼如下：

Person.cs文件。

using System;
using System.Collections.Generic;
using System.Text;

namespace InheritDemo
{
    public class Person
    {
        private string id;
        public string Id
        {
            get
            {
                return id;
            }
            set
            {
                id = value;
            }
        }
        private string name;
        public string Name
        {
            get
            {
                return name;
            }
            set
            {
                name = value;
            }
        }
        private int age;
        public int Age
        {
            get
            {
                return age;
            }
            set
            {
                age = value;
            }
        }
        private string gender;
        public string Gender
        {
            get
            {
                return gender;
            }
            set
            {
                gender = value;
            }
        }
         public Person(string name1, int age1, string gender1)
        {
            name = name1;
            age = age1;
            gender = gender1;
        }
        public void Display()
        {
            Console.WriteLine("{0}是{1}性，年齡為{2}",this.name,this.gender,this.age);
        }

    }

    public class Student : Person
    {
        private string class1;
        public string Class
        {
            get
            {
                return class1;
            }
            set
            {
                class1 = value;
            }
        }
        private string department;
        public string Department
        {
            get
            {
                return department;
            }
            set
            {
                department = value;
            }
        }
        private string no;
        public string No
        {
            get
            {
                return no;
            }
            set
            {
                no = value;
            }
        }
        public void Study()
        {
            Console.WriteLine("學生在學校學習。");
            Console.Read();
        }
    }
}
 

Program.cs文件。

using System;
using System.Collections.Generic;
using System.Text;

namespace InheritDemo
{
    class Program
    {
        static void Main(string[] args)
        {
            Person objPerson = new Person("XXX",XX,"X");
            objPerson.Display();
            Student objStudent = new Student();
            objStudent.Name = "XXX";
            objStudent.Age = XX;
            objStudent.Gender = "X";
            objStudent.Class = "XXXXXXXXX";
            objStudent.Display();
            Console.Read();
        }
    }
}

錯誤：“Person”方法沒有采用“0”個參數的重載。

原因：子類的構造函數沒有使用base指明調用父類哪個構造函數。

解決辦法：

using System;
using System.Collections.Generic;
using System.Text;

namespace InheritDemo
{
    public class Person
    {
        private string id;
        public string Id
        {
            get
            {
                return id;
            }
            set
            {
                id = value;
            }
        }
        private string name;
        public string Name
        {
            get
            {
                return name;
            }
            set
            {
                name = value;
            }
        }
        private int age;
        public int Age
        {
            get
            {
                return age;
            }
            set
            {
                age = value;
            }
        }
        private string gender;
        public string Gender
        {
            get
            {
                return gender;
            }
            set
            {
                gender = value;
            }
        }
        public Person() { }  //隱式的調用，base()，父類要提供無參的構造函數。
        public Person(string name1, int age1, string gender1)
        {
            name = name1;
            age = age1;
            gender = gender1;
        }
        public void Display()
        {
            Console.WriteLine("{0}是{1}性，年齡為{2}",this.name,this.gender,this.age);
        }

    }

    public class Student : Person
    {
        private string class1;
        public string Class
        {
            get
            {
                return class1;
            }
            set
            {
                class1 = value;
            }
        }
        private string department;
        public string Department
        {
            get
            {
                return department;
            }
            set
            {
                department = value;
            }
        }
        private string no;
        public string No
        {
            get
            {
                return no;
            }
            set
            {
                no = value;
            }
        }
        public Student() { }  //隱式的調用，base()，父類要提供無參的構造函數。
        public void Study()
        {
            Console.WriteLine("學生在學校學習。");
            Console.Read();
        }
    }
}