一、簡介

部落格參考將主要分析Object 是用來幹嘛的。它是 .NET Framework 中所有類的最終基類；它是型別層次結構的根。不管是系統定義的型別還是自定義的型別,都必須從Object派生。

參考：

網站1、微軟官網https://docs.microsoft.com/zh-cn/dotnet/api/system.object?redirectedfrom=MSDN&view=netframework-4.7.2

網站2、https://www.cnblogs.com/android-blogs/p/6494410.html

網站3、https://blog.csdn.net/wnln25/article/details/6678357

二、網站1：微軟官網的案例及分析

先把程式碼放出來,用到了兩個類。

program.cs: 

#region object類的應用舉例。
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Messaging;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using System.Xml.Linq;
namespace test
{
    class Program
    {
        static void Main(string[] args)
        {
            // Construct a Point object.
            Point p1 = new Point(1, 2);

            // Make another Point object that is a copy of the first.
            Point p2 = p1.Copy();

            // Make another variable that references the first Point object.
            Point p3 = p1;

            // The line below displays false because p1 and p2 refer to two different objects.
            Console.WriteLine(Object.ReferenceEquals(p1, p2));//ReferenceEquals表示比較物件。而p1、p2是不同的object，所以輸出結果為false

            // The line below displays true because p1 and p2 refer to two different objects that have the same value.
            Console.WriteLine(Object.Equals(p1, p2));//Equals表示比較數值。而p1、p2有相同的數值(1,2)，所以輸出結果為true。

            // The line below displays true because p1 and p3 refer to one object.
            Console.WriteLine(Object.ReferenceEquals(p1, p3));//p1、p3是相同的object，所以輸出結果為true

            // The line below displays: p1's value is: (1, 2)
            Console.WriteLine("p1's value is: {0}", p1.ToString());
            Console.ReadLine();
        }
    }
}
#endregion
 

Point.cs:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace test
{
    class Point
    {
        public int x, y;

        public Point(int x, int y)
        {
            this.x = x;
            this.y = y;
        }
        public override bool Equals(object obj)
        {
            // If this and obj do not refer to the same type, then they are not equal.
            if (obj.GetType() != this.GetType()) return false;

            // Return true if  x and y fields match.
            Point other = (Point)obj;
            return (this.x == other.x) && (this.y == other.y);
        }

        // Return the XOR of the x and y fields.
        public override int GetHashCode()
        {
            return x ^ y;
        }

        // Return the point's value as a string.
        public override String ToString()
        {
            return String.Format("({0}, {1})", x, y);
        }

        // Return a copy of this point object by making a simple field copy.
        public Point Copy()
        {
            return (Point)this.MemberwiseClone();
        }
    }
}
 

先看輸出結果：

False
True
True
p1's value is: (1, 2)

然後我們看單步除錯：

所以，我們要obj轉為Point型別： 

Point other = (Point)obj;

此時，

return (this.x == other.x) && (this.y == other.y);

other就是Point型別節點，我們就行直接拿出來比較即可：

三、網站3的程式碼

這篇部落格，只包含了Pragram.cs檔案。它和官網關於object類的分析，幾乎一致。

但是我們需要注意下面的轉換，這是常用轉換格式，特地列出，給我提醒：

 C c = obj as C;//往往採用這種格式將object型別轉化你想要的型別。我的Socket學習部落格，也採用到這種格式轉換。

好了，舉個特例延伸一下，你將obj轉為String、Socket、Point等等：

String  str = obj as String;
Socket socket = obj as Socket;
Point point = obj as Point; //string、Socket、Point是系統自定的類

Pragram.cs：

#region object類的應用舉例2。
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Messaging;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using System.Xml.Linq;
namespace test
{
    struct A
    {
        public int count;
    }
    class B
    {
        public int number;
    }

    class C
    {
        public int integer = 0;
        public override bool Equals(object obj)
        {
            C c = obj as C;//往往採用這種格式將object型別轉化你想要的型別。我的Socket學習部落格，也採用到這種格式轉換。
            if (c != null)
                return this.integer == c.integer;
            else
                return false;
        }
        public override int GetHashCode()
        {
            return 2 ^ integer;
        }
    }

    class Program
    {

        static void Main(string[] args)
        {
            A a1, a2;
            a1.count = 10;
            a2 = a1;

            //Console.Write(a1==a2);沒有定義“==”操作符
            Console.Write(a1.Equals(a2));//True
            Console.WriteLine(object.ReferenceEquals(a1, a2));//False

            B b1 = new B();
            B b2 = new B();

            b1.number = 10;
            b2.number = 10;
            Console.Write(b1 == b2);//False
            Console.Write(b1.Equals(b2));//False
            Console.WriteLine(object.ReferenceEquals(b1, b2));//False

            b2 = b1;
            Console.Write(b1 == b2);//True
            Console.Write(b1.Equals(b2));//True
            Console.WriteLine(object.ReferenceEquals(b1, b2));//True

            C c1 = new C();
            C c2 = new C();

            c1.integer = 10;
            c2.integer = 10;
            Console.Write(c1 == c2);//False
            Console.Write(c1.Equals(c2));//True
            Console.WriteLine(object.ReferenceEquals(c1, c2));//False

            c2 = c1;
            Console.Write(c1 == c2);//True
            Console.Write(c1.Equals(c2));//True
            Console.WriteLine(object.ReferenceEquals(c1, c2));//True
 
        }
    }
}
#endregion

好了，object就是這麼簡單。

好了，object就是這麼簡單

好了，object就是這麼簡單