CODEWITHSUNDEEP
c#asp.netlist
mary
mary

Reputation: 267

Remove objects with a duplicate property from List in c#

I Have a list and I want to create a new one without records with duplicate values

public List<links> results = new List<links>();
public List<links> final_results = new List<links>();
public class links
{
    public string url { get; set; }
    public string title { get; set; }
    public string description { get; set; }
    public int place { get; set; }
}

results gets it's values during code. Same record may occur with unique Place property but other properties are the same. I want to ommit duplicate records which have duplicate value in the url, title and description. I wrote this code but nothing changed:

     final_results = results .GroupBy(n => n.url).Select(g => g.FirstOrDefault()).ToList();

but when I bind my repeator to this new list nothing has changed. how can I ommit this duplicte value?

Upvotes: 0

Views: 4278

Answers (3)

Pranay
Pranay

Reputation: 430

try using Except extension method over the Links

final_results = results.Except(--duplicate criteria--)

Upvotes: 0

eocron
eocron

Reputation: 7536

Umm, you can just do:

var results = results.DistinctBy(x=> x.url);

Or if you want to exclude by multiple fields, simpliest is this:

var results = results.DistinctBy(x=> x.url + "," + x.title + "," + x.description);

If you want to do it properly - just override Equal and GetHashCode methods of your object and put your values in HashSet.

For DistinctBy to work, you can increase your .NET version or just use MoreLINQ.

Upvotes: 0

fubo
fubo

Reputation: 45947

If you want to suppress records with equality in 3 preperties url,titleand description, you have to group by all of them:

final_results = results.GroupBy(n => new {n.url, n.description, n.title})
                       .Select(g => g.FirstOrDefault()).ToList();

Upvotes: 6

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