Question

我无法理解为什么这个VB.net代码无法运行..

我要做的是if value1 > value2然后显示一个消息框，说明已过期，则显示消息框说明未过期。

If "4-3-13 10:54:22" > "15-3-13 12:23:30" Then
    MsgBox("Expired")
Else
    MsgBox("Not Expired")
End If

每当它出现时说过期甚至知道它不应该。

当我将其从15-3-13 12:23:30更改为1-3-13 12:23:30时，它仍然说已过期。

如果我将我的代码更改为：

If "4-3-13 10:54:22" < "15-3-13 12:23:30" Then
    MsgBox("Not Expired")
Else
    MsgBox("Expired")
End If

它仍然返回错误。

我如何做到：

DATE1 = 4-3-13 10:54:22

DATE2 = 15-3-13 12:23:30


IF DATE1 > DATE2 THEN
   Expired
else
   Not Expired

应该返回＆＃39;未过期＆＃39;

任何能够提供帮助的人......我无法工作吗？

Answer 1

"4-3-13 10:54:22" > "15-3-13 12:23:30" 
'This condition states that you are comaparring strings not date

为了得到你期望的结果，请这样做，

cdate("4-3-13 10:54:22") > cdate("15-3-13 12:23:30")
'Convert the strings into date and then compare it.

CDATE

Answer 2

这些date constants也会按预期执行，并且在程序运行时不受区域设置的约束：

#3/4/2013 10:54:22# > #3/15/2013 12:23:30#

请记住，您需要使用美国日期格式作为常量。

Answer 3

试试这个：

dim date1 as DateTime = DateTime.ParseExact("4-3-13 10:54:22", "MM-dd-yy HH:mm:ss")

dim date2 as DateTime = DateTime.ParseExact("15-3-13 12:23:30", "MM-dd-yy HH:mm:ss")

if date1 > date2 then
MsgBox("Expired")
else
MsgBox("Not Expired")
end if

Answer 4

代码如下：

If Today.Year - dExpiryDate.Value.Year = 0 Then
    If Today.Month - dExpiryDate.Value.Month < 0 Then
        LBExpiryDate.Text = "THE ID IS OK"
        LBExpiryDate.BackColor = Color.Green

    Else
        If Today.Month - dExpiryDate.Value.Month = 0 Then

            If Today.Day - dExpiryDate.Value.Day < 0 Then
                LBExpiryDate.Text = "THE ID IS OK"
                LBExpiryDate.BackColor = Color.Green
            Else
                LBExpiryDate.Text = "THE AGE IS EXPIRED "
                LBExpiryDate.BackColor = Color.Red
            End If
            Else
            LBExpiryDate.Text = "THE AGE IS EXPIRED "
            LBExpiryDate.BackColor = Color.Red

        End If
    End If
Else
    LBExpiryDate.Text = "THE AGE IS EXPIRED "
    LBExpiryDate.BackColor = Color.Red
End If
End If

查找日期是否超过另一个日期

4 个答案:

CDATE