VB.NET - Expirate Program

Question

Hello,

I would like to put an expiration date on my program, so that it doesn't run when it reaches the stipulated date. I'm using code below, and it works fine when I run on computers with "dd/mm/yyyy" date format, but when I run on computers with "mm/dd/yyy" date format, the condition doesn't work, and the program is executed. How can I use a condition that works on both date formats?

Dim dt1 As DateTime = DateTime.Now
Dim dt2 As DateTime = DateTime.Parse("31/12/2021")

        If dt1 >= dt2 Then
            MsgBox("Expired - Please Contact the Administrator")
            Application.Exit()

        End If

Answer 1

Hi @Sergio Siqueira ,
Use the following code to convert the date to "dd/MM/yyyy" date format.

Dim dt2 = DateTime.ParseExact("31/12/2021", "dd/MM/yyyy", Nothing)  

Convert to "MM/dd/yyyy" format.

dt2.ToString("MM/dd/yyyy")  

Hope it could be helpful.

Best Regards,
Xingyu Zhao
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Answer 2

You can use DateTime.ParseExact
(but if the user can change the System date, your test won't work...)

Answer 3

Hi,
I found out, now it's working

Than you a lot

Dim provider As New CultureInfo("en-US")
        Dim dt1 As Date = System.DateTime.Now
        Dim dt2 As DateTime = DateTime.ParseExact("31-12-2020", "mm-dd-yyyy", provider)

        If dt1 >= dt2 Then
            MsgBox("Expirou a Validade - Favor Contactar SERGIORS@")
            Me.Close()

        End If