C# DateTime去掉时分秒几种方法
例如: DtaeTime now = DateTime.Parse("2015/01/23 13:50:00")
Now().Date ==> 2015/1/23 0:00:00 //去掉时分秒,返回DateTime
Now().ToStringDateString==> 2015/1/23 //去掉时分秒,返回string
Now().ToString("d")==> 2015/1/23 //去掉时分秒,返回string
Now().ToString("yyyy-MM-dd") ==> 2015-01-23 //去掉时分秒,返回string
DateTime.Today ==> 2015/1/23 0:00:00 //当天日期无时分秒,返回DateTime