string str = DateTime.Parse("2011/4/8 0:00:00").ToString("yyyy-M-d");
//2011-4-8

------解决方案--------------------
C# code

dateString = "2011/4/8 0:00:00";
string format = "yyyy-mm-dd";
DateTime result = DateTime.ParseExact(dateString, format, null);

------解决方案--------------------
探讨


C# code

dateString = "2011/4/8 0:00:00";
string format = "yyyy-mm-dd";
DateTime result = DateTime.ParseExact(dateString, format, null);


参考http://msdn.microsoft.com/zh-cn/library/w2sa9yss