我刚才注意到一个多维数组在C＃中，不执行的IEnumerable＆LT; T＆GT; ，而它确实实现的IEnumerable 。对于一维数组，无论是的IEnumerable＆LT; T＆GT; 和的IEnumerable 的实施。

I have just noticed that a multidimensional array in C#, does not implement IEnumerable<T>, while it does implement IEnumerable. For single-dimensional arrays, both IEnumerable<T> and IEnumerable are implemented.

为什么这种差异？如果一个多维数组是的IEnumerable ，当然它也应该实现通用版本？我注意到这一点，因为我想在一个多维数组，除非你使用演员LT从而未能使用扩展方法; T＆GT; 或类似的;所以我可以肯定看到讨论是否多维数组实施的IEnumerable＆LT; T＆GT;

Why this difference? If a multi-dimensional array is IEnumerable, surely it should also implement the generic version? I noticed this because I tried to use an Extension method on a multidimensional array, which fails unless you use Cast<T> or similar; so I can definitely see the an argument for making multidimensional arrays implement IEnumerable<T>.

要澄清我在code的问题，我希望下面的code打印真的四倍，而它实际打印真，假，真，真：

To clarify my question in code, I would expect the following code to print true four times, while it actually prints true, false, true, true:

int[] singleDimensionArray = new int[10];
int[,] multiDimensional = new int[10, 10];

Debug.WriteLine(singleDimensionArray is IEnumerable<int>);
Debug.WriteLine(multiDimensional is IEnumerable<int>);
Debug.WriteLine(singleDimensionArray is IEnumerable);
Debug.WriteLine(multiDimensional is IEnumerable);

推荐答案

的CLR有阵列的两种不同类型：载体的这保证是一维具有下界0，和其可具有非零边界和秩0以外更一般的阵列

The CLR has two different kinds of arrays: vectors which are guaranteed to be one-dimensional with a lower bound of 0, and more general arrays which can have non-zero bounds and a rank other than 0.

在CLI规范第8.9.1：

From section 8.9.1 of the CLI spec:

此外，一个创建的载体   元素类型T，实现了   接口    System.Collections.Generic.IList＆LT; U＆GT;   （§8.7），其中U：= T

Additionally, a created vector with element type T, implements the interface System.Collections.Generic.IList<U> (§8.7), where U := T.

我不得不说，这似乎pretty的怪我。由于它已经实现了的IEnumerable 我不明白为什么它不应该执行的IEnumerable＆LT; T＆GT; 。它不会作出太大的意义落实的IList＆LT; T＆GT; ，但简单的通用接口就可以了。

I have to say it seems pretty weird to me. Given that it already implements IEnumerable I don't see why it shouldn't implement IEnumerable<T>. It wouldn't make as much sense to implement IList<T>, but the simple generic interface would be fine.

如果你想这样，你既可以调用演员LT; T＆GT; （如果你使用.NET 3.5）或写你自己的方法来遍历数组。为了避免铸造你必须编写其中发现每个维度的下限/上限，并取东西，这样你自己的方法。并不十分愉快的。

If you want this, you could either call Cast<T> (if you're using .NET 3.5) or write your own method to iterate through the array. To avoid casting you'd have to write your own method which found the lower/upper bounds of each dimension, and fetched things that way. Not terribly pleasant.