Web Parts: Using Filtered Data with SPList
This may be common knowledge, but up until recently I only knew how to retrieve the entire contents of a list with SPList, sorted by Sharepoint’s default settings with no filter. There’s an easy way to tailor the returned data to your liking, however. First, create a view that has the filter and sort options you want. This is important though: make sure that all three of the key fields (Title, Event, etc.) are displayed in your view. Tick the boxes next to, for example, Title (linked to item with edit menu), Title (linked to item), and Title. Otherwise, the Web Part will throw an exception if you attempt to display that field’s contents. This view shouldn’t be one that people will ever see; it’s just for your Web Part to use. Now, simply use the following code to only retrieve items included in and sorted by that view.
SPList list = web.Lists[listName];
SPView view = list.Views[viewName];
SPListItemCollection collection = list.GetItems(view);
foreach (SPListItem item in collection)
{
// Loop code
}
That’s all there is to it! Another thing, though. You may have noticed in previous posts that I would loop through items like this:
foreach (SPListItem item in list.items) { ... }
I also recently learned that doing that means Sharepoint will make a database call every iteration through the loop. That’s horribly inefficient. By loading the entire returned list into my variable collections, only a single query is executed and the server load is greatly reduced.
Resources I Used:
