C#中子類構造函數

時間 2019-11-14

標籤 c# 子類構造函數欄目 C# 简体版

原文原文鏈接

　　在C#中,一個子類繼承父類後,二者的構造函數又有何關係??函數

　1.隱式調用父類構造函數this

----------------父類spa

 1 public class Employee   
 2     {
 3        public Employee(){
 4            Console.WriteLine("父類無參對象構造執行!");
 5    }
 6        public Employee(string id, string name, int age, Gender gender)
 7        {
 8            this.Age = age;
 9            this.Gender = gender;
10            this.ID = id;
11            this.Name = name;
12        }
13         protected string ID { get; set; }       //工號
14         protected int Age { get; set; }         //年齡
15         protected string Name { get; set; }     //姓名
16         protected Gender Gender { get; set; }   //性別
17     }

----------------------子類code

public class SE : Employee
    {
        public SE() { } //子類
        public SE(string id, string name, int age, Gender gender, int popularity)
        {
            this.Age = age;
            this.Gender = gender;
            this.ID = id;
            this.Name = name;
            this.Popularity = popularity;
        }
        private int _popularity;
        //人氣
        public string SayHi()
        {
            string message;
            message = string.Format("你們好,我是{0},今年{1}歲,工號是{2},個人人氣值高達{3}!", base.Name, base.Age, base.ID, this.Popularity);
            return message;
        }
        public int Popularity
        {
            get { return _popularity; }
            set { _popularity = value; }
        }
    }

--------------------Main函數中調用orm

 static void Main(string[] args)
        {
            SE se = new SE("112","張三",25,Gender.male,100);
            Console.WriteLine(se.SayHi());
            Console.ReadLine();
}

-----------------運行結果對象

由上可知blog

建立子類對象時會首先調用父類的構造函數,而後纔會調用子類自己的構造函數.
若是沒有指明要調用父類的哪個構造函數,系統會隱式地調用父類的無參構造函數繼承

2.顯式調用父類構造函數get

C#中能夠用base關鍵字調用父類的構造函數.只要在子類的構造函數後添加":base(參數列表)",就能夠指定該子類的構造函數調用父類的哪個構造函數.
這樣能夠實現繼承屬性的初始化,而後在子類自己的構造函數中完成對子類特有屬性的初始化便可.string

------------------子類代碼變動爲其他不變

  public class SE : Employee
    {
        public SE() { } //子類
        public SE(string id, string name, int age, Gender gender, int popularity):base(id,name,age,gender)
        {
            //繼承自父類的屬性
            //調用父類的構造函數能夠替換掉的代碼
            //this.Age = age;
            //this.Gender = gender;
            //this.ID = id;
            //this.Name = name;
            this.Popularity = popularity;
        }
        private int _popularity;
        //人氣
        public string SayHi()
        {
            string message;
            message = string.Format("你們好,我是{0},今年{1}歲,工號是{2},個人人氣值高達{3}!", base.Name, base.Age, base.ID, this.Popularity);
            return message;
        }
        public int Popularity
        {
            get { return _popularity; }
            set { _popularity = value; }
        }


    }