C# 6.0 新功能Top 十

http://www.developer.com/net/csharp/top-10-c-6.0-language-features.html

1，单行函数表达式化

用=>简化只有一行的函数。

class Employee{   // Method with only the expression   public static int  CalculateMonthlyPay(int dailyWage)  => dailyWage * 30;}

以前需要显式地写判断非空的条件语句

private void GetMiddleName(Employee employee){   string employeeMiddleName = "N/A";   if (employee != null && employee.EmployeeProfile != null)      employeeMiddleName = employee.EmployeeProfile.MiddleName;}

private void GetMiddleName(Employee employee){   string employeeMiddleName = employee?.EmployeeProfile?.MiddleName ?? "N/A";}

不用再弄一个private的set和类变量了。如下：

class PeopleManager{   public List<string> Roles { get; } = new List<string>() { "Employee", "Managerial"};}

通过在类的定义这一层级声明构造函数的入参，取代一个单独的构造函数。入参的范围是类范围，且只在类的初始化时有效，与自动属性初始化器搭配起来好干活。

// Primary constructorclass Basket(string item, int price){   // Using primary constructor parameter values   // to do auto property initialization.   public string Item { get; } = item;   public int Price { get; } = price;}

避免在调用函数之前还得专门定义一个out类型的参数：

public bool ConvertToIntegerAndCheckForGreaterThan10(string value){   if (int.TryParse(value, out int convertedValue) && convertedValue > 10)   {      return true;   }   return false;}

这样就可以在一个异步操作中处理异步过程中的异常了。

public async void Process(){   try   {      Processor processor = new Processor();      await processor.ProccessAsync();   }   catch (Exception exception)   {      ExceptionLogger logger = new ExceptionLogger();      // Catch operation also can be aync now!!      await logger.HandleExceptionAsync(exception);   }}

可以选择不处理某些异常类型了。

public async void Process(){   try   {      DataProcessor processor = ne   }   // Catches and handles only non sql exceptions   catch (Exception exception) if(exception.GetType() != typeof(SqlException))   {      ExceptionLogger logger = new ExceptionLogger();      logger.HandleException(exception);   }}

以减少重复代码，比如using Console这个静态类：

using System;// A static class inclusionusing System.Console;namespace CSharp6Demo{   class Program   {      static void Main(string[] args)      {         WriteLine("Console. is not required as it is included in the usings!");      }   }}

可以认为是String.Format的改进，可以不再用替代符了，而是直接用变量。

static void Main(string[] args){   string name = "Robert";   string car = "Audi";   WriteLine("\{name}'s favourite car is {car}!");}

开源，且有一个接口供扩展。可以认为是“像服务一样的编译器”。