TimeSpan

TimeSpan.TotalSeconds 也是有正负数的， 判断时间段大小时，需要用 Math.Abs()来取绝对值判定。

Collections.Specialized

The System.Collections.Specialized namespace contains specialized and strongly-typed collections; for example, a linked list dictionary, a bit vector, and collections that contain only strings.

特殊功能的集合

  • NameValueCollection, 这个类型，有序的key-value pair, 并且相同key可以添加多条。 可用于formdata， header等。
  • System.Collections.Specialized.CollectionsUtil.CreateCaseInsensitiveHashTable(), 创建字母大小写不敏感hashtable

HashTable

As entries are added to a hashtable, the hashtable’s actual load factor increases, and when the actual load factor reaches the maximum load factor value, the number of buckets in the hashtable is automatically increased by approximately a factor of two (to be precise(精确的说), the number of hashtable buckets is increased to the smallest prime number（素数） that is larger than twice the current number of hashtable buckets).