string s = " from dual union all "; s = s.Trim().TrimEnd("union all".ToCharArray());结果是"from d"
http://www.cnblogs.com/carekee/articles/2094731.html
C#中Trim()、TrimStart()、TrimEnd()的用法
原文：http://www.cnblogs.com/yangai/p/5764787.html
