C# 语言版本

（摘自：维基百科）https://en.wikipedia.org/wiki/C_Sharp_(programming_language)

Versions

Version	Language specification			Date	.NET Framework	Visual Studio
	ECMA	ISO/IEC	Microsoft
C# 1.0	December 2002	April 2003	January 2002	January 2002	.NET Framework 1.0	Visual Studio .NET 2002
C# 1.1 and 1.2			October 2003	April 2003	.NET Framework 1.1	Visual Studio .NET 2003
C# 2.0	June 2006	September 2006	September 2005[c]	November 2005	.NET Framework 2.0	Visual Studio 2005
C# 3.0	None[d]		August 2007	November 2007	.NET Framework 2.0 (Except LINQ)[36] .NET Framework 3.0 (Except LINQ)[36] .NET Framework 3.5	Visual Studio 2008 Visual Studio 2010
C# 4.0			April 2010	April 2010	.NET Framework 4	Visual Studio 2010
C# 5.0	In Progress[37]	None[d]	June 2013	August 2012	.NET Framework 4.5	Visual Studio 2012 Visual Studio 2013
C# 6.0	None[d]		Draft	July 2015	.NET Framework 4.6	Visual Studio 2015
C# 7.0			None	March 2017	.NET Framework 4.6.2	Visual Studio 2017
C# 7.1	None	None	None	August 2017	.NET Framework 4.6.2	Visual Studio 2017

New features

C# 2.0

• Generics^[38]
• Partial types^[38]
• Anonymous methods^[38]
• Iterators^[38]
• Nullable types^[38]
• Getter/setter separate accessibility^[38]
• Method group conversions (delegates)^[38]
• Co- and Contra-variance for delegates^[38]
• Static classes^[38]
• Delegate inference^[38]

C# 3.0

• Implicitly typed local variables^[39]
• Object and collection initializers^[39]
• Auto-Implemented properties^[39]
• Anonymous types^[39]
• Extension methods^[39]
• Query expressions^[39]
• Lambda expression^[39]
• Expression trees^[39]
• Partial methods^[40]

C# 4.0

• Dynamic binding^[41]
• Named and optional arguments^[41]
• Generic co- and contravariance^[41]
• Embedded interop types ("NoPIA")^[41]

C# 5.0^[42]

• Asynchronous methods^[43]
• Caller info attributes^[43]

C# 6.0

• Compiler-as-a-service (Roslyn)
• Import of static type members into namespace^[44]
• Exception filters^[44]
• Await in catch/finally blocks^[44]
• Auto property initializers^[44]
• Default values for getter-only properties^[44]
• Expression-bodied members^[44]
• Null propagator (null-conditional operator, succinct null checking)^[44]
• String interpolation^[44]
• nameof operator^[44]
• Dictionary initializer^[44]

C# 7.0^[45]

• Out variables
• Pattern matching
• Tuples
• Deconstruction
• Local functions
• Digit separators
• Binary literals
• Ref returns and locals
• Generalized async return types
• Expression bodied constructors and finalizers
• Expression bodied getters and setters

C# 7.1^[46]

• Async main
• Default literal expressions
• Inferred tuple element names
•