Find out index of collectionlist with specific value in specific column

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I have BidList (ObservableCollection) and I want to find index of the row in which for example Id==25.

How to do that?

What I have tried:

Tried with FindIndex and it doesn't work in my case

Posted 23-Jun-19 3:47am

Sinisa Janjetovic

Updated 23-Jun-19 15:55pm

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Maciej Los · Accepted Answer · 2019-06-23T04:13:00

Solution 1

Try something like this:

C#

var itemindex =  BidList.IndexOf(BidList.Where(x=>x.Id==25).FirstOrDefault());

Posted 23-Jun-19 4:13am

Maciej Los

Comments

Sinisa Janjetovic 23-Jun-19 10:42am

Thank you, but I am getting -1, and definitely it is not. I tested it with Id==20, and I should get 19.

Or I put this code on wrong place? I pasted it in part of the code I wrote in my question.

Should I keep symbol x as you wrote or I should replace it with something?

Maciej Los 23-Jun-19 11:12am

I have no idea why you're getting -1.
Yes, you can replace [x] with any symbol or name, for example: Where(item=>item.Id==20)

Sinisa Janjetovic 23-Jun-19 11:35am

Thank you, it works great. I've found one internal mistake, everything is proper.

Maciej Los 23-Jun-19 11:53am

Great. Can you accept my answer as a solution?

Sinisa Janjetovic 23-Jun-19 18:48pm

Yes, of course, you helped me a lot

Maciej Los 24-Jun-19 4:03am

Thank you.
Cheers
Maciej

BillWoodruff · Accepted Answer · 2019-06-23T15:56:00

One of the many powerful features of 'ObservableCollection<T> is the "state" information the 'CollectionChanged EventHandler gives you. By keeping track of the last change data, you can often avoid unnecessary code, and/or enable an 'undo feature:

bool suppressOCChangeAction = false;
bool keepOCLastChangeData = true;

NotifyCollectionChangedAction lastAction;
int prevNdx;
int newNdx;
IList oldItems;
IList newItems;

private void OCOnCollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
{
    if (suppressOCChangeAction) return;

    if (keepOCLastChangeData)
    {
        lastAction = e.Action;
        prevNdx = e.OldStartingIndex;
        newNdx = e.NewStartingIndex;
        oldItems = e.OldItems;
        newItems = e.NewItems;
    }

    switch (e.Action)
    {
        case NotifyCollectionChangedAction.Add:
            break;
        case NotifyCollectionChangedAction.Remove:
            break;
        case NotifyCollectionChangedAction.Replace:
            break;
        case NotifyCollectionChangedAction.Move:
            break;
        case NotifyCollectionChangedAction.Reset:
            break;
    }
}