Dictionary<string, string> openWith = new Dictionary<string, string>();

            //添加元素

            openWith.Add("txt", "notepad.exe");

            openWith.Add("bmp", "paint.exe");

            openWith.Add("dib", "paint.exe");

            openWith.Add("rtf", "wordpad.exe");

            Console.WriteLine("For key = \"rtf\", value = {0}.", openWith["rtf"]);

            //更改值

            openWith["rtf"] = "winword.exe";

            Console.WriteLine("For key = \"rtf\", value = {0}.", openWith["rtf"]);

            //遍历key

            foreach (string key in openWith.Keys)

            {

                Console.WriteLine("Key = {0}", key);

            }

            //遍历value

            foreach (string value in openWith.Values)

            {

                Console.WriteLine("value = {0}", value);

            }

            //遍历字典

            foreach (KeyValuePair<string, string> kvp in openWith)

            {

                Console.WriteLine("Key = {0}, Value = {1}", kvp.Key, kvp.Value);

            }

            Console.WriteLine("===============");

            //删除元素

            openWith.Remove("rtf");

            //遍历字典

            foreach (KeyValuePair<string, string> kvp in openWith)

            {

                Console.WriteLine("Key = {0}, Value = {1}", kvp.Key, kvp.Value);

            }