ListControl with custom comparer

[Franco]

Good afternoon.
With the old RadListBox I could write code like this:
    _radListBox.Items.Sort(comparer)
with my custom comparer. How can achive this with the new RadListControl?

Thank you very much.
Gianfranco

[Peter]

Hi Franco,

Thank you for writing.

Sorting in RadListControl is controlled only via the SortStyle property. It supports ascending sort style, descending sort style and no sort style. Setting sorting through code looks like this:

radListControl1.SortStyle = Telerik.WinControls.Enumerations.SortStyle.Ascending;

So, if you want to use custom comparer method for sorting operation you should use this approach:

List<RadListDataItem> sortList = new List<RadListDataItem>(radListControl1.Items);
sortList.Sort(MyOwnComparer);
radListControl1.Items.Clear();
radListControl1.Items.AddRange(sortList);

I hope this helps. Best wishes,
Peter
the Telerik team

[Eric]

Hi!!

I'm following the suggestion here, and I created a custom IComparer to order the list as numbers. But I'm having some problems creating a list from the RadListControl.List Method. It always return for me a list of RadListDataItem, but all of them are returned as Nothing. I'm using VB language. Here is the piece of code:

'my comparer:
Dim myComparer As IComparer(Of RadListDataItem) = New RadListDataItemNumericComparer()

'here it creates the list with the number of items I have, but all items are Nothing (the same as null in C#):
Dim sortList As New List(Of RadListDataItem)(myRadList.Items)

'so, it fails here, because I have a list of Nothing objects:
sortList.Sort(myComparer)
myRadList.Items.Clear()
myRadList.Items.AddRange(sortList)

How can I make it create a proper list of RadListDataItem? Could it be a bug at the RadListControl component?

Thanks in advanced!
Eric

[Peter]

Hello Eric,

Thank you for writing.

I was not able to reproduce the described issue. Having in mind the numerous scenarios possible with this control, it will be best if you send us a sample project that reproduces the issue. This will allow us to investigate it and provide you with proper support.

I am looking forward to your reply.

All the best,
Peter
the Telerik team