How to disable sorting in a List?

Question

I'm using a List and sort items.

objListOrder.Sort(
delegate(Order p1, Order p2)
{
    return p1.Title.CompareTo(p2.Title);
}

I'm having an issue where I need to disable sort and order the items in the order they were added in the list, not in the alphabetical order of corresponding keys.

Is there a way to clear sorting after sort?

So you don't want to *disable* sorting at all, you want to *override* the default `Sort` behaviour - 2 different things. — James, Mar 03 '14 at 12:51
To do that, you need to keep the original list untouched and sort copies instead. There is no "undo"-functionality in a list. — Håkan Fahlstedt, Mar 03 '14 at 12:52

score 2 · Answer 1 · answered Mar 03 '14 at 12:54

2

Is there a way to clear sorting after sort?

No. When you need to use a sorted list use

var newList = objListOrder.OrderBy(p=>p.Title).ToList();

Which creates a sorted copy of the original List

answered Mar 03 '14 at 12:54

EZI

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score 1 · Accepted Answer · answered Mar 03 '14 at 12:52

1

Is there a way to clear sorting after sort?

No, lists do not keep information about the order in which their items were added.

But of course you could add an extra field like OriginalIndex to you object and sort the list by this field.

answered Mar 03 '14 at 12:52

AlexD

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James · Answer 3 · 2014-03-03T13:01:25.210

0

It sounds like what you are after here is for a call to the Sort method to have no affect. Given List<T> guarantees ordering just have your comparer delegate return 0, this effectively tells the list that the items should not be shifted

delegate(Order p1, Order p2) {
    return 0;
}

See Comparison<>

edited Mar 03 '14 at 13:01

answered Mar 03 '14 at 12:53

James

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How to disable sorting in a List?

3 Answers3