DATEDIFF in VB.Net 1

[kermitforney]

Trying to get this to run correctly in VB.NET (code behind ASP.Net). Something is off with the Syntax and I am not sure what it is. Any suggestions??

intDateDiff = Me!txtToDate - Me!txtFromDate
      If intDateDiff > 84 Or (intDateDiff Mod 7) <> 0 Then
        MsgBox "The difference between the From and To dates must be no greater than 12 weeks."

 

[kermitforney]

Of course without the messagebox. )

 

[shaunk]

Try this.

If IsDate(TextBox1.Text) And IsDate(TextBox2.Text) Then
                Dim dt1 As DateTime = DateTime.Parse(TextBox1.Text)
                Dim dt2 As DateTime = DateTime.Parse(TextBox2.Text)
                Dim days As Int16 = DateDiff("d", dt1, dt2)
                Label1.Text = "Date Interval is: " & days.ToString & " days."
            Else
                Label1.Text = "Date interval not calculated: Input boxes must contain valid dates."
            End If

The risk with keeping an open mind is having your brains fall out.
Shaunk

 

[kermitforney]

Actually, what I need is to compare the DateDiff between the startdate text box and the enddate text box. If the difference is greater than 84 days or not divisible by 7 (. . Mod <> 7), then I would like it to error out.

 

[jmeckley]

use a custom field validator and define the logic in the servervalidate event handler.

Jason Meckley
Programmer
Specialty Bakers, Inc.

 

[kermitforney]

Can't I accomplish this in VB via Code Behind?? I am not familiar with ASP.Net.

 

[jmeckley]

I am not familiar with ASP.Net

but your using asp.net, at that's implied because this is the asp.net forum.

Can't I accomplish this in VB via Code Behind??

you are because you will wire the validation logic to the control via a custom field validator.

Jason Meckley
Programmer
Specialty Bakers, Inc.

 

[kermitforney]

I apologize for the mispost, but I wasn't sure where to post this.

I will look into custom field validation.

Thanks, Jmeck.

 

[shaunk]

I think the following code-behind meets your requirement, but the validation is better placed in a customvalidator control. I prefer client-side Javascript for custom validation logic that doesn't require database access, because it avoids a round-trip to the server.
A brief and crude comparison of client-side validation versus server-side validation is:
"Client side validation is fast but vunerable to security risks and can be disabled by a hacker. Server-side validation is slow but safe."

If IsDate(StartDate.Text)And IsDate(EndDate.Text) Then
 Dim StartRange As DateTime = DateTime.Parse(StartDate.Text)
 Dim EndRange As DateTime = DateTime.Parse(EndDate.Text)
 Dim days As Int16 = DateDiff("d", StartRange, EndRange)
If days Mod 7 <> 0 Or days > 84 Then
    Response.Write("Perform your error routine")
End If
 Label1.Text = "Date Interval is: " & days.ToString & " days."
 Else
   Label1.Text = "Date interval not calculated: Input  boxes must contain valid dates."
End If

The risk with keeping an open mind is having your brains fall out.
Shaunk