// 声明Dictionary并初始化

            Dictionary<string, string> dic = new Dictionary<string, string>() {

                {"1", "one"},

                {"2", "two"},

                {"3", "three"}

            };

            // 获得KeyList

            List<string> keyList = dic.Keys.ToList();

            // 获得ValueList

            List<string> valueList = dic.Values.ToList();

            // 获得KeyValuePairList

            List<KeyValuePair<string, string>> kvList = dic.ToList();

            // KeyValuePairList -> Dictionary

            Dictionary<string, string> dic2 = kvList.ToDictionary(item => item.Key, item => item.Value);

            // 在KeyValuePairList中添加一个重复Key，转换为Dictionary时异常

            kvList.Add(new KeyValuePair<string, string>("1", "1"));

            Dictionary<string, string> dic3 = kvList.ToDictionary(item => item.Key, item => item.Value);    // 发生异常