在. net中，列表被表示为数组。因此，与LinkedList相比，使用普通List会更快。这就是为什么上面的人看到他们看到的结果。

Why should you use the List? I would say it depends. List creates 4 elements if you don't have any specified. The moment you exceed this limit, it copies stuff to a new array, leaving the old one in the hands of the garbage collector. It then doubles the size. In this case, it creates a new array with 8 elements. Imagine having a list with 1 million elements, and you add 1 more. It will essentially create a whole new array with double the size you need. The new array would be with 2Mil capacity however, you only needed 1Mil and 1. Essentially leaving stuff behind in GEN2 for the garbage collector and so on. So it can actually end up being a huge bottleneck. You should be careful about that.

本质上，. net中的List<>是数组的包装器。LinkedList<>是一个链表。所以问题归结为，数组和链表之间的区别是什么，以及什么时候应该使用数组而不是链表。可能在你决定使用哪个时最重要的两个因素可以归结为:

Linked lists have much better insertion/removal performance, so long as the insertions/removals are not on the last element in the collection. This is because an array must shift all remaining elements that come after the insertion/removal point. If the insertion/removal is at the tail end of the list however, this shift is not needed (although the array may need to be resized, if its capacity is exceeded). Arrays have much better accessing capabilities. Arrays can be indexed into directly (in constant time). Linked lists must be traversed (linear time).

我问了一个类似的关于LinkedList集合性能的问题，发现Steven Cleary的Deque c#实现是一个解决方案。与Queue集合不同，Deque允许前后移动项目。它类似于链表，但性能有所改进。

使用LinkedList的常见情况是这样的:

假设您想要从一个字符串列表中删除许多特定的字符串，这些字符串的大小很大，比如100,000。要删除的字符串可以在HashSet dic中查找，字符串列表中应该包含30,000到60,000个这样的需要删除的字符串。

那么用于存储100,000个字符串的列表的最佳类型是什么?答案是LinkedList。如果它们存储在数组列表中，则遍历它并删除匹配的字符串将占用 到数十亿次操作，而使用迭代器和remove()方法只需要大约100,000次操作。

LinkedList<String> strings = readStrings();
HashSet<String> dic = readDic();
Iterator<String> iterator = strings.iterator();
while (iterator.hasNext()){
    String string = iterator.next();
    if (dic.contains(string))
    iterator.remove();
}

在. net中，列表被表示为数组。因此，与LinkedList相比，使用普通List会更快。这就是为什么上面的人看到他们看到的结果。

Why should you use the List? I would say it depends. List creates 4 elements if you don't have any specified. The moment you exceed this limit, it copies stuff to a new array, leaving the old one in the hands of the garbage collector. It then doubles the size. In this case, it creates a new array with 8 elements. Imagine having a list with 1 million elements, and you add 1 more. It will essentially create a whole new array with double the size you need. The new array would be with 2Mil capacity however, you only needed 1Mil and 1. Essentially leaving stuff behind in GEN2 for the garbage collector and so on. So it can actually end up being a huge bottleneck. You should be careful about that.

Edit

请阅读对这个答案的评论。人们说我没有 适当的测试。我同意这不应该是一个可以接受的答案。就像我一样 我做了一些测试，想和大家分享。

最初的回答…

我发现了有趣的结果:

// Temporary class to show the example
class Temp
{
    public decimal A, B, C, D;

    public Temp(decimal a, decimal b, decimal c, decimal d)
    {
        A = a;            B = b;            C = c;            D = d;
    }
}

链表(3.9秒)

        LinkedList<Temp> list = new LinkedList<Temp>();

        for (var i = 0; i < 12345678; i++)
        {
            var a = new Temp(i, i, i, i);
            list.AddLast(a);
        }

        decimal sum = 0;
        foreach (var item in list)
            sum += item.A;

列表(2.4秒)

        List<Temp> list = new List<Temp>(); // 2.4 seconds

        for (var i = 0; i < 12345678; i++)
        {
            var a = new Temp(i, i, i, i);
            list.Add(a);
        }

        decimal sum = 0;
        foreach (var item in list)
            sum += item.A;

即使你只是访问数据，本质上也要慢得多!!我说永远不要使用linkedList。

下面是另一个执行大量插入的比较(我们计划在列表中间插入一个项)

链表(51秒)

        LinkedList<Temp> list = new LinkedList<Temp>();

        for (var i = 0; i < 123456; i++)
        {
            var a = new Temp(i, i, i, i);

            list.AddLast(a);
            var curNode = list.First;

            for (var k = 0; k < i/2; k++) // In order to insert a node at the middle of the list we need to find it
                curNode = curNode.Next;

            list.AddAfter(curNode, a); // Insert it after
        }

        decimal sum = 0;
        foreach (var item in list)
            sum += item.A;

榜单(7.26秒)

        List<Temp> list = new List<Temp>();

        for (var i = 0; i < 123456; i++)
        {
            var a = new Temp(i, i, i, i);

            list.Insert(i / 2, a);
        }

        decimal sum = 0;
        foreach (var item in list)
            sum += item.A;

有插入位置引用的链表(。04秒)

        list.AddLast(new Temp(1,1,1,1));
        var referenceNode = list.First;

        for (var i = 0; i < 123456; i++)
        {
            var a = new Temp(i, i, i, i);

            list.AddLast(a);
            list.AddBefore(referenceNode, a);
        }

        decimal sum = 0;
        foreach (var item in list)
            sum += item.A;

因此，只有当你计划插入几个项目，并且你也在某个地方有你计划插入项目的引用时，才使用链表。只是因为你必须插入很多项，这并不会使它更快，因为搜索你想要插入的位置需要时间。