C# 6.0可能的新特性
1、主构造函数（Primary Constructors）
主构造函数给类中的变量赋值
Before
public class Point {
private int x, y;
public Point(int x, int y)
this.x = x;
this.y = y;
}
}
After
public class Point(int x, int y) {
private int x, y;
}
2、自动属性赋值（Auto Properties）
Before
class Point
{
public int X { get; private set; }
public int Y { get; private set; }
public Point()
{
this.X = 100;
this.Y = 100;
}
}
After
class Point
{
public int X { get; private set; } = 100;
public int Y { get; private set; } = 100;
}
3、using静态类（Static type using statements;）
using会把引用类的所有静态方法导入到当前命名空间
Before
public double A { get { return Math.Sqrt(Math.Round(5.142)); } }
After
using System.Math;
...
public double A { get { return Sqrt(Round(5.142)); } }
4、Property Expressions
Before
public double Distance {
get { return Math.Sqrt((X * X) + (Y * Y)); }
}
After
public double Distance => Math.Sqrt((X * X) + (Y * Y));
初看起来像Lambda表达式，其实和Lambda无关系。
5. Method Expressions
Before
public Point Move(int dx, int dy) {
return new Point(X + dx1, Y + dy1);
}
After
public Point Move(int dx, int dy) => new Point(X + dx, Y + dy);
这个和Property Expressions类似
6、Params for enumerables
Before
Do(someEnum.ToArray());
...
public void Do(params int[] values) { ... }
After
Do(someEnum);
public void Do(params IEnumerable<Point> points) { ... }
以前params是只可以修饰array类型的参数，现在多了一些类型
7、Monadic null checking(null检查运算符)
Before
if (points != null) {
var next = points.FirstOrDefault();
if (next != null && next.X != null) return next.X;
}
return -1;
After
var bestValue = points?.FirstOrDefault()?.X ?? -1;
这个少了好几行代码，赞啊
8、Constructor type parameter inference
Before
var x = MyClass.Create(1, "X");
...
public MyClass<T1, T2> Create<T1, T2>(T1 a, T2 b) {
return new MyClass<T1, T2>(a, b);
}
After
var x = new MyClass(1, "X");
9、 Inline declarations for out params(内联out参数定义)
Before
int x;
int.TryParse("123", out x);
After
int.TryParse("123", out int x);
说实话，这个很常用。
当然，C# 6.0的全部新特性不止这么多，限于篇幅，就整理这些，若想了解更多，请参考下面的链接。
参考资料：
http://roslyn.codeplex.com/wikipage?title=Language%20Feature%20Status&referringTitle=Documentation
http://en.wikipedia.org/wiki/.NET_Framework_version_history
http://damieng.com/blog/2013/12/09/probable-c-6-0-features-illustrated
http://www.kunal-chowdhury.com/2012/07/evolution-of-c-10-50-what-are-new.html
原文: