如何lambda表达式内部工作？ [英] How do lambda expressions work internally?
问题描述
虽然答案寻找到这个问题：的为什么是匿名方法中不允许out参数？我有一点点失落关于如何lambda表达式和匿名方法的实际工作。
While looking up the answer to this question: "Why is an out parameter not allowed within an anonymous method?" I've got a little lost about how do lambda expression and anonymous methods actually work.
在评论JaredPar指出，想象一下，例如，该OUT参数所指的堆栈中的局部变量。该拉姆达可以在未来任意点执行，从而可以执行时堆栈帧不再有效
In the comments JaredPar states that "Imagine for instance that the out parameter referred to a local variable on the stack. The lambda can execute at any arbitrary point in the future and hence could execute when that stack frame was no longer valid".
我指出，如果那不是与任何其他变量的情况下......这基本上让我怀疑什么，我真的了解lambda表达式。
I pointed out if wouldn't that be the case with any other variable... which basically make me wonder what to I really know about lambda expressions.
我心目中的东西是这样的：
The thing I have in mind is something like this:
public void Foo(ComplexObject val, out SomeDelegate outDelegate)
{
ComplexObject obj = new ComplexObject(val)
SomeDelegate = delegate(int other) { return (obj.value * other); }
}
public void Bar()
{
SomeDelegate MyDel = null;
Foo(5, out MyDel);
int finalRes = MyDel(100);
// Whatever
}
在这种情况下我真的不知道发生了什么。 obj是堆栈这将不再是关于方法的返回有效所以annonymous方法应该可以（如果适用）来真正知道这是引用类型和复制，而不是参考价值的，如果它在一个参考...为什么不REF如果用例或多或少是相同的PARAMS工作？
In that situation I don't really know what's happening. obj is a reference on the stack which would no longer be valid on method return so the annonymous method should be able (if that works) to actually know that's a reference type and copy the reference instead of the value, if it does... why wouldn't ref params work if the "use case" is more or less the same?
推荐答案
我做了一个相当广泛的博客系列闭包的内部是如何工作的。这是写在VB.Net实施封锁，但底层细节非常类似于C＃的。它应该提供你正在寻找
I did a fairly extensive blog series on how closures work internally. It's written for the VB.Net implementation of closures but the underlying details are very similar to C#'s. It should provide the answers you're looking for
下面是链接到所有其他条款
Here is the link to part 6 which links to all of the other articles
- http://blogs.msdn.com/jaredpar/archive/2007/08/06/closures-in-vb-part-6-limitations.aspx
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