为什么.NET 4.6的具体code编译当目标框架的旧版本？ [英] Why Does .NET 4.6 Specific Code Compile When Targeting Older Versions of the Framework?

问题描述

我有一个目标较旧版本的.NET框架（.NET 4.5.2）的一个项目。我安装了Visual Studio 2015年（以及.NET 4.6我的机器上）。我注意到，如果我用发布.NET 4.6的C＃语言功能/ C＃6，但它仍然编译。如果我的项目的目标框架为＆lt; .NET 4.6，应该不是这个不能编译：

I have a project that targets older versions of the .NET framework (.NET 4.5.2). I installed Visual Studio 2015 (and therefore .NET 4.6 on my machine). I noticed that if I use C# language features released in .NET 4.6/C# 6, it still compiles. If my project's target framework is < .NET 4.6, shouldn't this not compile:

    public string MyExpressionBodyProperty => "1";

    //auto properties are new in C# 6
    public string MyAutoProperty { get; } = "1";

    private static void MethodThatUsesNameOf(string filename)
    {
        if (filename == null) 
        {
            //nameof was released in C# 6
            throw new ArgumentException("The file does not exist.", nameof(filename));
        }
    }

我如何能确保我只使用了与我针对的框架版本工作的.NET语言的特点？

How can I ensure I'm only using .NET language features that work with the framework version I'm targeting?

推荐答案

.NET Framework版本和C＃语言的版本是不同的东西。 C＃的6语言功能

The .NET Framework version and the C# language version are different things. The C# 6 language features

public string MyAutoProperty { get; } = "1";
nameof(filename)

可以通过VS 2015年被编入code表示针对早期框架。

can be compiled by VS 2015 into code that targets earlier frameworks.

我如何能确保我只使用了与我针对的框架版本工作的.NET语言的特点？

How can I ensure I'm only using .NET language features that work with the framework version I'm targeting?

如果您尝试使用.NET 4.6框架的功能，你会得到一个合适的编译错误，如果你的目标更早的框架。

If you try to use a .NET 4.6 Framework feature, you will get an appropriate compiler error if you are targeting an earlier framework.

我将能够部署此code到机器，没有.NET 4.6？

Would I be able to deploy this code to machine which did not have .NET 4.6?

是的，你会的。只要部署机具有与所述一个你在VS2015目标兼容的框架。

Yes, you would. As long as the deployment machine has a framework compatible with the one you target in VS2015.

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