PlanetWrox

RiversideAce · #1 (**permalink**) January 7th, 2011, 06:12 AM

Hello.

I have recently been through the book Beginning ASP.NET 4 in C# and VB and have found a small bug in the code of the www.PlanetWrox.com web site (i.e. built from the book).

On the Gig Pics page, when you select an item from the drop down list that has more than 3 pictures (i.e. more than one page), go to the next or last page (Next or Last button), then select an album with up to 3 pictures (i.e. one page), the ListView control shows "No data was returned".

For example -
1) go to www.planetwrox.com
2) Select Gig Pics from menu
3) Select Pam's Pics from drop down
4) Click the "Last" button
5) Select Bubba Lines from the dropdown - "No data was returned" is shown
6) Select Brothers In Arms from dropdown - Album cover pic shows
7) Re-select Bubba Lines from dropdown - now we see a pic of Mr Incredible

I presume that there's a nice easy fix for this... some C# code for the dropdown On Select method to initialise the ListView, perhaps.

I would really appreciate it if someone could advise.

Many thanks.

Imar · #2 (**permalink**) January 7th, 2011, 08:39 AM

Hi there,

Yes, you're correct. This is indeed a problem.

Quote:

I presume that there's a nice easy fix for this... some C# code for the dropdown On Select method to initialise the ListView, perhaps

And that's indeed the fix. For a detailed explanation, check out this post:

http://leedumond.com/blog/resetting-...in-a-listview/

The following should do the trick:

Code:

protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
{
  CommandEventArgs commandEventArgs = new CommandEventArgs("First", "");
  DataPager pager = ListView1.FindControl("DataPager1") as DataPager;
  if (pager != null)
  {
    NextPreviousPagerField nextPreviousPagerField = pager.Fields[0] as NextPreviousPagerField;
    if (nextPreviousPagerField != null)
    {
      nextPreviousPagerField.HandleEvent(commandEventArgs);
    }
  }
}

This also requires the following addition to the DropDownList in markup:

Code:

<asp:DropDownList ID="DropDownList1" runat="server" AutoPostBack="True" DataSourceID="EntityDataSource1" DataTextField="Name" DataValueField="Id" onselectedindexchanged="DropDownList1_SelectedIndexChanged" />

For future posts like these, you're better off posting in the book's own forum category: http://p2p.wrox.com/book-beginning-asp-net-4-c-vb-560/

Hope this helps,

Imar