C# |装箱拆箱

原文:https://www.geeksforgeeks.org/c-sharp-boxing-unboxing/

拳击和拆箱是【c#中的一个重要概念。C# Type 系统包含三种数据类型 : 值类型(int、char 等)、引用类型(object) 和指针类型。基本上，它将值类型转换为引用类型，反之亦然。装箱和取消装箱实现了类型系统的统一视图，其中任何类型的值都可以被视为对象。

c# 打拳

转换一个值类型(字符，整型等)的过程。)到一个参考型(物体)叫做拳。
装箱是使用对象类型(超类型)的隐式转换过程。
值类型始终存储在堆栈中。引用的类型存储在堆中。
例:

```cs int num = 23; // 23 will assigned to num Object Obj = num; // Boxing

```
Description : First declare a value type variable (num), which is integer type and assigned it with value 23. Now create a references object type (obj) and applied Explicit operation which results in num value type to be copied and stored in object reference type obj as shown in below figure :
让我们用 C# 编程代码来理解拳击:

```cs // C# implementation to demonstrate // the Boxing using System; class GFG {

// Main Method     static public void Main()     {

// assigned int value         // 2020 to num         int num = 2020;

// boxing         object obj = num;

// value of num to be change         num = 100;

System.Console.WriteLine         ("Value - type value of num is : {0}", num);         System.Console.WriteLine         ("Object - type value of obj is : {0}", obj);     } } ```

输出:

```cs Value - type value of num is : 100 Object - type value of obj is : 2020

```

在 C# 中脱氧

将参考类型转换为值类型的过程称为拆箱。
它是显式的转换过程。
例:

```cs int num = 23; // value type is int and assigned value 23 Object Obj = num; // Boxing int i = (int)Obj; // Unboxing

```
Description : Declaration a value type variable (num), which is integer type and assigned with integer value 23. Now, create a reference object type (obj).The explicit operation for boxing create an value type integer i and applied casting method. Then the referenced type residing on Heap is copy to stack as shown in below figure :
让我们来理解用 C# 编程代码打开的锁:

```cs // C# implementation to demonstrate // the Unboxing using System; class GFG {

// Main Method     static public void Main()     {

// assigned int value         // 23 to num         int num = 23;

// boxing         object obj = num;

// unboxing         int i = (int)obj;

// Display result         Console.WriteLine("Value of ob object is : " + obj);         Console.WriteLine("Value of i is : " + i);     } } ```

输出:

```cs Value of ob object is : 23 Value of i is : 23

```

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