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Changing page size should reset page index

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Grid

This is a migrated thread and some comments may be shown as answers.

25 Answers, 1 is accepted

answered on 07 Jan 2008, 07:19 PM

I understand that it is possible to code this functionality manually, so that is one possible solution. However, I was wondering if this functionality could be included by default in the control itself in the future.

I tried thinking about it, and I can't think of a scenario where the user wouldn't want to go back to the first page when the page size changes. The only case I could think of is when the user is on the first page and changes the size, then it is fine to stay on the current page and see more or fewer records. However, that only makes sense with the first page, and resetting the page index here wouldn't affect this scenario.

In all other cases, the user is likely to lose records currently displayed.
For example, suppose the user is on page 2, displaying records 11-20 of 30. If the user changes the page size from 10 to 20, the user will now see records 21-30. All records previously displayed will no longer be visible.
Similarly, if the user changes the page size from 10 to 5, records 6-10 will be displayed. Again, all records previously displayed will no longer be visible.

It seems the most common (perhaps exclusive) usage would be to have the page index reset automatically when changing page size. If so, could that logic be included in the control automatically?

Thanks for considering this suggestion.

David
(Sorry, I accidentially posted under the wrong account, so the name is wrong.)

answered on 31 Jul 2008, 07:32 AM

Hello,

I've found also that PageSizeChanged event fires EVERY TIME (on every postback), if PageSize is set using ASP.NET skin.

I've created a skin, defined PageSize there, used that skin on my grid and now on every postback in the grid (for example, sorting or page change) I get that PageSizeChanged event.

Another bug: setting PageSize by user and then hitting corresponding button DOES NOT change grid's PageSize property. Thats why we are using PageSize in a skin ;-) I've tested that behavior - in the Request.Form variables I can see CORRECT value - 20 (entered by user) BUT grid after postbacl will show again defaul 10 rows per page.

I'm using Q1 Prometheus

answered on 01 Sep 2008, 07:48 AM

Hi Alexander,

Thank you for the additional information.

Basically, the page size should be retained when you commit a postback from another control on the page. Nevertheless, if you want to ensure that the page size is applied as expected after you perform custom filtering through your set of controls, merely set the PageSize property of the master table from your postback event handler and invoke the Rebind() method of the grid.

Additionally, to set the PageSize in the relevant textbox from the pager, access the pager using the GetItems(itemType) method of the grid and locate the textbox by its id with the FindControl(id) method. Review the following article from the online help for more info.

Best regards,
Stephen
the Telerik team

Check out Telerik Trainer, the state of the art learning tool for Telerik products.

answered on 01 Sep 2008, 05:54 PM

Hi,

i've succeeded in finding CORRECT page size value - it was really matter of bottom pager. And when I use submit controls from the grid - page size, page number - everything works nice!

However, problem remained: when submit is NOT from within telerik grid control - assigning CORRECT page size value to grid property does not affect actual page size value, which remains:
1) = 10, if there is no page size value indicated in grid skin file
2) = value in grid skin file if it's indicated there

I suspect for some reason it's being reset again to this WRONG - default value - somewhere later, not in MY code...

Alas, I cannot send the ticket, because our client still have not bought trial version and trial support period is over (> 60 days)

answered on 08 Sep 2008, 03:35 PM

Hello Alexander,

I reviewed your sample along with the custom classes in it and found the following method which performs a recursive loop through the page controls:

    
                   public Control FindControlRecursive(Control root, string id) 
        
                    { 
        
                        Control result = null; 
        
                        if (root.ID == id) 
        
                        { 
        
                            result = root; 
        
                        } 
        
                        else 
        
                        { 
        
                            foreach (Control ctl in root.Controls) 
        
                            { 
        
                                Control foundCtl = FindControlRecursive(ctl, id); 
        
                                if (foundCtl != null) 
        
                                { 
        
                                    controlList.Add(foundCtl); 
        
                                } 
        
                            } 
        
                        } 
        
                        return result; 
        
                    }

Note that this might cause some problems if the Controls collection of the grid is accessed early in the page lifecycle (this is discussed in the following KB article and is applicable for the ASP.NET AJAX version of the grid, too).

Can this be the reason for the issue you experience? Does avoiding this iteration make a difference?

On the other hand, what happens if the class from the code-behind of the page holding the grid extends directly the System.Web.UI.Page class instead of your custom class? Test that and if the problem remains please isolate a fully functional working subset of your project and send it attached to a support ticket.

In order to be allowed to start support tickets, download another trial version of RadControls for ASP.NET AJXA from our site to receive additional 60 days support.

Best regards,
Stephen
the Telerik team

Check out Telerik Trainer, the state of the art learning tool for Telerik products.

answered on 12 Dec 2011, 11:00 PM

Hi Sebastian,

I'm confused about whether the page index is really retained as you say it is... I agree it would be nice for the same reasons you say (the user wants to see more records beyond the record they are already on) but this is not my experience that it does that. I have a grid with CustomPaging set to true and when the pagesize is changed it always goes back to the first page, which I don't want. I want it to remember the item the user was on and then show the new amount of records on that same page.

And according to this Telerik example: http://demos.telerik.com/aspnet-ajax/grid/examples/programming/custompaging/defaultvb.aspx it is essentially instructing us to manually handle paging indexes, which seems to contradict your statement (Jan 7th, and Sept.1 2008 of this thread) that it is automatically retained. Am I missing something? Thanks in advance.

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Changing page size should reset page index

25 Answers, 1 is accepted