C# 6.0 預覽 (preview in Roslyn)
微軟在今年4月的 //BUILD 大會中宣佈了 Roslyn 這個計畫，其中對 .NET 開發者最大的意義，不僅在於開放了 .NET Compiler 的原始碼，同時還能參與下一代 .NET 語言的改進；也就是說，也許各位的建議及貢獻能成為下一版本的 .NET 的一部份!
Rosly 網址: https://roslyn.codeplex.com/
隨著計劃的進行，下一版本的 .NET 規格也進入倒數，以下影片簡單展示在 C# 6.0 中的 Primary Constructor, Getter-only auto properties, Method expressions 及 Property expressions:
C#6.0 預覽: Primary Constructor, Getter-only auto properties, Method expressions and Property expressions.
各位可以在 Roslyn 中直接觀察下一代 C#/VB 的實作狀況 (as of 2014/09/11): https://roslyn.codeplex.com/wikipage?title=Language%20Feature%20Status&referringTitle=Home
| Feature | Example | C# | VB |
|---|---|---|---|
| Primary constructors | class Point (int x, int y) { … } | Done | Maybe |
| Auto-property initializers | public int X { get; set; } = x; | Done | Exists |
| Getter-only auto-properties | public int Y { get; } = y; | Done | Done |
| Using static members | using System.Console; … Write(4); | Done | Exists |
| Dictionary initializer | new JObject { ["x"] = 3, ["y"] = 7 } | Done | Planned |
| Indexed member initializer | new JObject { $x = 3, $y = 7 } | Withdrawn | Planned |
| Indexed member access | c. $name = c. $first + " " + c. $last; | Withdrawn | Exists |
| Declaration expressions | int.TryParse(s, out var x); | Done | Maybe |
| Await in catch/finally | try … catch { await … } finally { await … } | Done | Planned |
| Exception filters | catch(E e) if (e.Count > 5) { … } | Done | Exists |
| Typecase | Select Case o : Case s As String : … | No | Maybe |
| Guarded cases | Select Case i : Case Is > 0 When i Mod 2 = 0 | No | Maybe |
| Partial modules | Partial Module M1 | N/A | Done |
| Partial interfaces | Partial Interface I1 | Exists | Done |
| Multiline string literals | "Hello <newline> World" | Exists | Done |
| Year-first date literals | Dim d = #2014-04-03# | N/A | Done |
| Binary literals | 0b00000100 | Planned | Planned |
| Digit separators | 0xEF _ FF _ 00 _ A0 | Planned | Planned |
| Line continuation comments | Dim addrs = From c in Customers ' comment | N/A | Done |
| TypeOf IsNot | If TypeOf x IsNot Customer Then … | N/A | Done |
| Expression-bodied members | public double Dist => Sqrt(X * X + Y * Y); | Planned | No |
| Event initializers | new Customer { Notify += MyHandler }; | Planned | Planned |
| Null propagation | customer ? .Orders ? [5] ? .$price | Done | Planned |
| Semicolon operator | (var x = Foo() ; Write(x) ; x * x) | Maybe | Maybe |
| Private protected | private protected string GetId() { … } | Withdrawn | Withdrawn |
| Params IEnumerable | int Avg(params IEnumerable<int> numbers) { … } | Planned | Planned |
| Constructor Inference | new Tuple(3, "three", true); | Maybe | Maybe |
| String interpolation | " \{ p.First } \{ p.Last } is \{ p.Age } years old." | Maybe | Maybe |
| TryCast for nullable | Dim x = TryCast(u, Integer? ) | Exists | Planned |
| Delegate combination with + | d1 += d2 | Exists | Planned |
| Implicit implementation | Class C : Implicitly Implements I | Exists | Planned |
| nameof operator | string s = nameof( Console.Write ) ; | Exists | Planned |
| Strict modules | Strict Module M | Exists | Planned |
| Faster CInt | Dim x = CInt(Math.Truncate(d)) | | Exists | Planned |
| #pragma | #Disable Warning BC40008 | Exists | Planned |
| Checked and Unchecked blocks | Checked : x += 1 : End Checked | Exists | Maybe |
| Field targets on autoprops | <Field: Serializable> Property p As Integer | Planned | Planned |
| If(b,e1,e2) uses type context | Dim x As Integer? = If(b,1,Nothing) | N/A | Maybe |