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C# 6.0 新特性汇总

1. 静态using(static using)

静态using声明允许不使用类名直接调用静态方法。

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The static using declaration allows invoking static methods without the class

name.

In C# 5

using System;

Console.WriteLine( "Hello, World!" );

In C# 6

using static System.Console;

WriteLine( "Hello, World" );

2. 表达式方法(Expression-Bodied Methods)

使用表达式方法,只有一条语句的方法可以使用lambda语法写。

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With expression-bodied methods, a method that includes just one statement can

be written with the lambda syntax.

In C# 5

public bool IsSquare(Rectangle rect)

{

return rect.Height == rect.Width;

}

In C# 6

public bool IsSquare(Rectangle rect) => rect.Height == rect.Width;

3. 表达式属性(Expression-Bodied Properties)

跟表达式方法类似,只有一个get访问器的单行属性可以使用lambda语法写。

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Similar to expression-bodied methods, one-line properties with only a get accessor

can be written with the lambda syntax

In C# 5

public string FullName

{

get

{

return FirstName + "" + LastName;

}

}

In C# 6

public string FullName => FirstName + "" + LastName;

4. 自动属性初始化器(Auto-Implemented Property Intializers)

自动属性可以使用属性初始化器初始化。

Auto-implemented properties can be initialized with a property initializer.

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In C# 5

public class Person

{

public Person()

{

Age = 24;

}

public int Age { get ; set ;}

}

In C# 6

public class Person

{

public int Age { get ; set ;} = 42;

}

5. 只读自动属性(Read-Only Auto Properties)

C# 5需要完整的属性语法实现只读属性,C# 6可以使用自动属性实现。

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To implement read-only properties, C# 5 requires the full property syntax. With

C# 6, you can do this using auto-implemented properties.

In C# 5

private readonly int _bookId;

public BookId

{

get

{

return _bookId;

}

}

In C# 6

public BookId { get ;}

6. nameof操作符(nameof Operator)

字段、属性、方法和类型的name可以通过nameof访问。使用nameof,可以方便的重构name变化。

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With the new nameof operator , names of fields, properties, methods, or types can

be accessed. With this , name changes are not missed with refactoring.

 

In C# 5

public void Method( object o)

{

if (o == null ) throw new ArgumentNullException( "o" );

In C# 6

public void Method( object o)

{

if (o == null ) throw new ArgumentNullException(nameof(o));

7. Null传递操作符(Null Propagation Operator)

Null传递操作符简化了空值检查。

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The null propagation operator simplifies null checks.

In C# 5

int ? age = p == null ? null : p.Age;

var handler = Event;

if (handler != null )

{

handler(source, e);

}

In C# 6

int ? age = p?.Age;

handler?.Invoke(source, e);

8. 字符串插值(String Interpolation)

字符串差值移除了对string.Format的调用,使用表达式占位符取代数字格式占位符。

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The string interpolation removes calls to string .Format. Instead of using

numbered format placeholders in the string , the placeholders can include

expressions.

In C# 5

public override ToString()

{

return string .Format( "{0}, {1}" , Title, Publisher);

}

In C# 6

public override ToString() => $ "{Title} {Publisher}" ;

9. 字典初始化器(Dictionary Initializers)

字典可以使用类似集合的字典初始化器初始化。

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Dictionaries can now be initialized with a dictionary initializer—similar to the

collection initializer.

In C# 5

var dict = new Dictionary< int , string >();

dict.Add(3, "three" );

dict.Add(7, "seven" );

In C# 6

var dict = new Dictionary< int , string >()

{

[3] = "three" ,

[7] = "seven"

};

10. 异常过滤器(Exception Filters)

异常过滤器允许你在捕获异常前进行过滤。

Exception filters allow you to filter exceptions before catching them.

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In C# 5

try

{

//etc.

} catch (MyException ex)

{

if (ex.ErrorCode != 405) throw ;

// etc.

}

In C# 6

try

{

//etc.

} catch (MyException ex) when (ex.ErrorCode == 405)

{

// etc.

}

11. 在Catch使用Await(Await in Catch)

await可以在catch块中直接使用,C# 5中需要变通使用。

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await can now be used in the catch clause. C# 5 required a workaround.

In C# 5

bool hasError = false ;

string errorMessage = null ;

try

{

//etc.

} catch (MyException ex)

{

hasError = true ;

errorMessage = ex.Message;

}

if (hasError)

{

await new MessageDialog().ShowAsync(errorMessage);

}

In C# 6

try

{

//etc.

} catch (MyException ex)

{

await new MessageDialog().ShowAsync(ex.Message);

}

以上所述是小编给大家介绍的C# 6.0 新特性汇总,希望对大家有所帮助,如果大家有任何疑问请给我留言,小编会及时回复大家的。在此也非常感谢大家对服务器之家网站的支持!

原文链接:http://HdhCmsTestcnblogs测试数据/zhangdk/archive/2016/09/27/5914182.html

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