Shulou(Shulou.com)06/02 Report--

小编给大家分享一下C#3.0中如何实现自动属性和对象初始化器，相信大部分人都还不怎么了解，因此分享这篇文章给大家参考一下，希望大家阅读完这篇文章后大有收获，下面让我们一起去了解一下吧!

1.匿名属性

定义属性如下：

public class Employee{public int Id { get; set; }public string Name { get; set; }public string Sex { get; set; }public int Age { get; set; }public string BirthDate { get; set; }}在C#3.0 之前的写法如下：public class Employee{private int _id;private string _name;private string _sex;private int _age;private string _birthDate; public int Id{get { return _id; }set { _id = value; }}public string Name{get { return _name; }set { _name = value; }}public string Sex{get { return _sex; }set { _sex = value; }}public int Age{get { return _age; }set { _age = value; }}public string BirthDate{get { return _birthDate; }set { _birthDate = value; }}}

仅从代码量上就前者比后者减少了2/3的代码，这对提高效率是显而易见的，那么这些代码都到哪里去了呢？其实那些额外的代码都是由编译器为我们完成的，编译器会将那些我们"省去"的代码编译成托管IL代码的时候补进去，两者中代码在最终生成的IL代码的体积是差不多的。

上图中的IL代码中我们看到了k_BackingField之类的字段就是编译器自动产生的字段代码。

2.对象初始化器，原来的对象初始化都要进行先创建构造方法，然后才能进行成员的相关操作，C#3.0 提供了对象成员的直接初始化的能力，和初始化一个集合或者是数组一样来初始化对象。

相面来看，通过对象初始化器对上面的的Employee类进行进行调用：

Employee employee = new Employee { Id = 1, Name = "蓝之风", Age = 24, BirthDate ="1984-10-21", Sex = "男" };

Console.WriteLine("编号;{0}", employee.Id);

Console.WriteLine("姓名:{0}", employee.Name);

Console.WriteLine("年龄:{0}", employee.Age);

Console.WriteLine("生日:{0}", employee.BirthDate);

Console.WriteLine("性别:{0}", employee.Sex);

Console.WriteLine("请按任意键继续...");

Console.ReadLine();

这句Employee employee = new Employee { Id = 1, Name = "蓝之风", Age = 24,BirthDate = "1984-10-21", Sex = "男" };

就是对象的初始化，看到代码很简洁，输出的结果如下：

在C#3.0之前的做法是：

Employee employee = new Employee();

employee.Id = 1;

employee.Name = "蓝之风";

employee.Age = 24;

employee.BirthDate = "1984-10-21";

employee.Sex = "男";

Console.WriteLine("编号;{0}", employee.Id);

Console.WriteLine("姓名:{0}", employee.Name);

Console.WriteLine("年龄:{0}", employee.Age);

Console.WriteLine("生日:{0}", employee.BirthDate);

Console.WriteLine("性别:{0}", employee.Sex);

Console.WriteLine("请按任意键继续...");

Console.ReadLine();

或者通过重载构造方法的方式来初始化这些属性，二者的达到的效果是相同的，但是前者使用起来方便了些，代码量减少了许多，这个过程是怎么完成的呢？其实C#本身并没有太大的变化，这些都是在语法上的一些改变，使得编写代码的时候更方便效率更高，把一些编译器可以推断出来完成的工作让编译器来做了，编译器在编译程序的时候将我们没有实现的代码替我们实现来生成IL代码的：

method private hidebysig static void Main(string[] args) cil managed

{

.entrypoint

// 代码大小 175 (0xaf)

.maxstack 2

.locals init ([0] class CS30.Employee employee,

[1] class CS30.Employee 'g__initLocal0')

IL_0000: nop

IL_0001: newobj instance void CS30.Employee::.ctor()

IL_0006: stloc.1

IL_0007: ldloc.1

IL_0008: ldc.i4.1

IL_0009: callvirt instance void CS30.Employee::set_Id(int32)

IL_000e: nop

IL_000f: ldloc.1

IL_0010: ldstr bytearray (DD 84 4B 4E CE 98 ) // ..KN..

IL_0015: callvirt instance void CS30.Employee::set_Name(string)

IL_001a: nop

IL_001b: ldloc.1

IL_001c: ldc.i4.s 24

IL_001e: callvirt instance void CS30.Employee::set_Age(int32)

IL_0023: nop

IL_0024: ldloc.1

IL_0025: ldstr "1984-10-21"

IL_002a: callvirt instance void CS30.Employee::set_BirthDate(string)

IL_002f: nop

IL_0030: ldloc.1

IL_0031: ldstr bytearray (37 75 ) // 7u

IL_0036: callvirt instance void CS30.Employee::set_Sex(string)

IL_003b: nop

IL_003c: ldloc.1

IL_003d: stloc.0

IL_003e: ldstr bytearray (16 7F F7 53 3B 00 7B 00 30 00 7D 00 ) // ...S;.{.0.}.

IL_0043: ldloc.0

IL_0044: callvirt instance int32 CS30.Employee::get_Id()

IL_0049: box [mscorlib]System.Int32

IL_004e: call void [mscorlib]System.Console::WriteLine(string,

object)

IL_0053: nop

IL_0054: ldstr bytearray (D3 59 0D 54 3A 00 7B 00 30 00 7D 00 ) // .Y.T:.{.0.}.

IL_0059: ldloc.0

IL_005a: callvirt instance string CS30.Employee::get_Name()

IL_005f: call void [mscorlib]System.Console::WriteLine(string,

object)

IL_0064: nop

IL_0065: ldstr bytearray (74 5E 84 9F 3A 00 7B 00 30 00 7D 00 ) // t^..:.{.0.}.

IL_006a: ldloc.0

IL_006b: callvirt instance int32 CS30.Employee::get_Age()

IL_0070: box [mscorlib]System.Int32

IL_0075: call void [mscorlib]System.Console::WriteLine(string,

object)

IL_007a: nop

IL_007b: ldstr bytearray (1F 75 E5 65 3A 00 7B 00 30 00 7D 00 ) // .u.e:.{.0.}.

IL_0080: ldloc.0

IL_0081: callvirt instance string CS30.Employee::get_BirthDate()

IL_0086: call void [mscorlib]System.Console::WriteLine(string,

object)

IL_008b: nop

IL_008c: ldstr bytearray (27 60 2B 52 3A 00 7B 00 30 00 7D 00 ) // '`+R:.{.0.}.

IL_0091: ldloc.0

IL_0092: callvirt instance string CS30.Employee::get_Sex()

IL_0097: call void [mscorlib]System.Console::WriteLine(string,

object)

IL_009c: nop

IL_009d: ldstr bytearray (F7 8B 09 63 FB 4E 0F 61 2E 95 E7 7E ED 7E 2E 00 // ...c.N.a...~.~..

2E 00 2E 00 ) // ....

IL_00a2: call void [mscorlib]System.Console::WriteLine(string)

IL_00a7: nop

IL_00a8: call string [mscorlib]System.Console::ReadLine()

IL_00ad: pop

IL_00ae: ret

} // end of method Program::Main以上是"C#3.0中如何实现自动属性和对象初始化器"这篇文章的所有内容，感谢各位的阅读!相信大家都有了一定的了解，希望分享的内容对大家有所帮助，如果还想学习更多知识，欢迎关注行业资讯频道!

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