Listview, general question

nanonerd · June 24th, 2012, 04:34 PM

Hi,

I am wondering on the flexibility of using a listview control. E.g., Can I add code to check a value within a list item, and then decide whether to change the background color of the list item box? Would this code go into an Item event? I would have guessed the ItemCreating event except that this event doesn't exist. Maybe this custom code can go in the ItemCreated event?

I was using a user control prior because it gave me great ease and flexibility on layout. And I could simply put code into the code behind. However, since everyone is telling me that I should use a listview control, I would like to know if it is just as easy to custom code the layout design with a listview.

Thanks,

- nano

Imar · June 25th, 2012, 03:03 AM

Well, I suggested a ListView because it seems a lot easier than generating user controls on the fly and manage your own state. That's not to say that you have to use the ListView and that a UC is a bad practice; it all depends on your design and what you're trying to accomplish.

That said, ItemCreated is indeed a good place. Here's a quick example:

Code:

protected void ListView1_ItemCreated(object sender, ListViewItemEventArgs e)
{
  Label description = e.Item.FindControl("DescriptionLabel") as Label;
  Picture picture = e.Item.DataItem as Picture;
  if (picture != null)
  {
    if (picture.Id  > 5)
    {
      description.CssClass = "Alert";
    }
  }
}

I am using FindControl to find a control inside the ItemTemplate. I then cast DataItem to the item I am binding to the control; a Picture in my case. When the picture is not null I am changing the appearance of the Label by assigning a CssClass. In this example, I am only doing that when the Id is > 5, but clearly this is just an example and you can apply any business logic you see fit.

Hope this helps,

Imar

June 25th, 2012, 05:11 AM

The method of data presentation depends on the number of headers in the grid. Upon display of each row the grid searches for a header for it, and if it doesn't find it, a header from the previous hierarchy level is used. This enables to implement the grid and tree list view in a single component.
http://www.dapfor.com/en/net-suite/net-grid/tutorial

Imar · June 25th, 2012, 05:17 AM

How does this help the OP? THis is a WinForms grid....

Imar

nanonerd · June 25th, 2012, 06:08 AM

Thanks for the answer/insight.

I really appreciate the code sample as it provides a great guide ... I'll def attempt to use this in the future ...

- nano