Invalid CurrentPageIndex value. It must be >= 0 and < the PageCoun

[Juan G.]

I have a DataGrid in which I use paging, as well as Delete buttons. My
program works perfectly, except when I attempt to delete the only item on the
page; I have no trouble deleting an item when there are more than one item
on a page. For example, I have a list that is three pages long; there is
currently only one item on page 3. I receive the above error message when I
try to delete this item. Do I need to include a special line of code to
prevent this from happening?

 

[Teemu Keiski]

Hi,

yes, it needs to be handled manually
http://forums.asp.net/798105/ShowPost.aspx

 

[Juan G.]

Thank you, Teemu. I read this thread, and I think I might understand. I code
in VB.Net, so the C# answer was a little confusing. They mentioned this code:

if ((DataGrid.Items.Count % DataGrid.PageSize) == 1
&& DataGrid.CurrentPageIndex != 0 )
DataGrid.CurrentPageIndex = DataGrid.PageCount - 2;

Would it be correct to translate this as:

If (DataGrid.Items.Count OR DataGrid.PageSize = 1
AND DataGrid.CurrentPageIndex NotEqual 0 ) Then
DataGrid.CurrentPageIndex = DataGrid.PageCount - 2

Also, do I place this command at the beginning of my Delete Row sub (BEFORE
I delete the row)?

Thanks again for your help.

Juan G.

 

[Juan G.]

I just did some research, and I think the correct VB.NET syntax would be:

If ((Math.IEEERemainder(DataGrid.Items.Count, DataGrid.PageSize)=1) AndAlso
(DataGrid.CurrentPageIndex <>0)) Then DataGrid.CurrentPageIndex =
DataGrid.PageCount-2

End If

 

[Teemu Keiski]

Hello,

it's crucial that you just have correct CurrentPageIndex when the grid is
rebound again. So, if deleting would fail then you wouldn't change the
index, but if it succeeds and you rebind the list, then you'd want to
correct the index.

 

[Teemu Keiski]

And by the way

if ((DataGrid.Items.Count % DataGrid.PageSize) == 1

means modulus e.g

If (DataGrid.Items.Count Mod DataGrid.PageSize) = 1