C#数组计算哈希Hash

说明

在一个数组的列表中，想要去重复，可能要经过相互比较，这种效率就会变的比较差，但要对数组进行 Hash，还是在一套公认的方法

 namespace MyTestDemo
{
    class MathUtil
    {
        /// <summary>
        /// 获取数组内容的哈希，因为数组的默认哈希值,即使内容相同，数组的默认哈希码也是唯一的
        /// </summary>
        /// <remarks>
        /// See Jon Skeet (C# MVP) response in the StackOverflow thread
        /// http://stackoverflow.com/questions/263400/what-is-the-best-algorithm-for-an-overridden-system-object-gethashcode
        /// </remarks>
        /// <param name="array">要取Hash值的数组.</param>
        /// <returns>当前数组的Hash值</returns>
        public static int GetHashCode<T>(T[] array)
        {
            // if non-null array then go into unchecked block to avoid overflow
            if (array != null)
            {
                unchecked
                {
                    int hash = 17;

                    // get hash code for all items in array
                    foreach (var item in array)
                    {
                        hash = hash * 23 + ((item != null) ? item.GetHashCode() : 0);
                    }

                    return hash;
                }
            }

            // if null, hash code is zero
            return 0;
        }
    }
}