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 constructor
class 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 inclusion
using 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”。

C# 6.0 新功能Top 10