在ByRef内部方法上指定OutAttribute当前是否有作用？ [英] Does specifying the OutAttribute on ByRef internal methods currently do anything?

问题描述

VB.NET没有 out 参数，但是您可以指定< Out（）>在COM和P / Invoke方法上使用ByRef ，以使外部方法获得相同的效果。

VB.NET doesn't have out parameters, but you can specify <Out()> ByRef on COM and P/Invoke methods to get the same effect for external methods.

在内部方法（即仅方法）上指定相同.NET代码调用）实际上有助于抖动（或VB.NET编译器）吗？还是当前仅用作程序员注释？

Does specifying the same on internal methods (i.e. methods only called by .NET code) actually help the Jitter (or VB.NET compiler)? Or is it currently only useful as a programmer note.

是否有可能在以后的抖动中使用它，或者在编译时会丢失此属性？

Is it possible it could be used in a future Jitter, or is this attribute lost when compiling?

推荐答案

我已经确认VB.NET < Out（）> 可以导致C＃客户端需要 out 自变量，因此它似乎实际上是相同的。

I've confirmed a VB.NET <Out()> does cause a C# client to require out arguments, so it does seem to be effectively the same.

也有C＃客户将其带有当前值的参数传递给方法，但这并不奇怪，因为与COM或P / Invoke情况不同，无需进行任何编组。 （而且C＃不允许直接通过 out 参数设置属性，因此似乎没有办法查看C＃是否可以优化先前的

Also a C# client passes in its arguments with current values into the method, but that's not surprising because, unlike the COM or P/Invoke cases, there's no marshalling to do. (And C# won't allow a property to be set by an out argument directly, so there doesn't seem to be a way to see if C# would optimise away a previous unneeded assignment.)

所以看来答案是，它确实可以帮助将来的C＃客户端使用该代码，并且如果抖动曾经调整了C＃等效项，它将完成同样在这里。尽管由于存在VB之类的语言，所以它不能做很多事情，因为它们不尊重 Out 属性本身。

So it seems the answer is it does help possible future C# clients use the code, and if the jitter ever adjusts the C# equivalent, it would do the same here. Though because languages like VB exist, it can't do much because they don't respect the Out attribute themselves.

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