把string[]数组转成string字符串

数组：string[] s = { "a", "b", "c", "d", "e" };
①Join转换字符串：string str1 = string.Join(",", s);

②格式化字符串：string str2 = String.Format("{0},{1},{2},{3},{4}", s);

http://blog.163.com/hanyu_accp/blog/static/2058220232012316101752354/