怎样获得某一天的上一天日期?

[ahking]

从文本框获得一日期字符串:2001-12-1,怎样计算该天的上一天的正确日期,注意闰月闰年!!!

[ahking]

当数据为从文本框取得，格式为2001-01-01，
即sdate="2001-01-01",怎么取上一天？？？

[zhq2000]

DateTime dt = DateTime.Parse( sdate );
DAteTime dtPrev = dt.AddDays(-1);

[ahking]

to:zhq2000(俗子)
编译错误!!

Compiler Error Message: BC30684: 'DateTime' is a type and cannot be used as an expression.

[ahking]

dim dtrq as DateTime = new DateTime.Parse(stdate);
dim dtPrev as dateTime = new dtrq.AddDays(-1);
如果按照VB语法，则出现以下错误！！！
Compiler Error Message: BC30037: Character is not valid.

[dengjiangyang]

取日期 -1
例如：
取当天日期Now.ToShortDateString
取昨天的日期Now.Date.AddDays(-1).ToShortDateString

[ahking]

同样错误！！！！
Compiler Error Message: BC30037: Character is not valid.

Source Error:



Line 81: stdate="2001-12-18"
Line 82:
Line 83: dim dtrq as DateTime = DateTime.Parse(stdate);
Line 84: dim dtPrev as dateTime = dtrq.AddDays(-1);
Line 85:


Source File: D:\www\hzbtest.aspx Line: 83

[zhq2000]

我这没问题，你试试：


using System;

class Demo
{
public static void Main(string[] args)
{
if(args.Length < 1)
{
Console.WriteLine("Usage: Demo <filename>");
return;
}

DateTime dt = DateTime.Parse(args[0] );

Console.WriteLine("Year={0}\nMonth={1}\nDay={2}\nHour={3}\nMinute={4}\nSecond={5}" ,
dt.Year , dt.Month , dt.Day , dt.Hour , dt.Minute , dt.Second);

}
}

[ahking]

我是在asp.net环境下啊！

[zhq2000]

用法不对！
dim dtrq as DateTime = DateTime.Parse(stdate);
dim dtPrev as DateTime = dtrq.AddDays(-1);

[dengjiangyang]

如文本框Id=txtDate
dim getdate as datetime
getdate=convert.ToDateTime(txtDate.Text)

[triout]

出现上面的问题是否你系统的日期格式设置的问题？请检查。

[Ganz]

dateadd("d",-1,"2001-12-1")