foreach是否从C＃BlockingCollection中删除？

Question

does anyone know if, when iterating on a C# BlockingCollection<>, the elements are taken from the collection, in the same way that BlockingCollection.Take() does for example?

BlockingCollection<int> q = new BlockingCollection<int>();
[...]
foreach(int i in q)
{
    //does q still contain i?
}

Thanks

EDIT: Of course I meant BlockingCollection, but for some reason got BlockingQueue in my head and used that.

Answer 1

The BlockingCollection<T> enumerator does NOT remove items from the collection.

However, the enumerator returned from BlockingCollection<T>.GetConsumingEnumerable() DOES remove items from the collection.

Answer 2

foreach simply enumerates across a collection. It never removes anything from any collection.

Answer 3

There is no BlockingQueue<T> in the .NET libraries.

Assuming

1. You're talking about BlockingCollection<T> : No. using foreach calls the GetEnumerator method, which returns an IEnumerator . Standard implementations of an IEnumerator simply enumerate through the elements in the collection without any observable side effects. Since MSDN doesn't say otherwise regarding BlockingCollection<T> specifically, it is safe to assume that this specific implementation also has no observable side effects.

2. You're talking about a third-party library: You'll have to check its implementation, but I think it's safe to assume it doesn't remove anything from the collection.

Edit : Actually, because BlockingCollection wraps around an IProducerConsumerCollection<T> , BlockingCollection uses the enumerator of the underlying (internal) collection. None of the IProducerConsumerCollection<T> implementations provided by .NET modify the collection.