select distinct property from list c# code example

Example 1: c# distinct by property

objList.Select(o=>o.typeId).Distinct()

Example 2: c# distinct comparer multiple properties

List<Person> distinctPeople = allPeople
  .GroupBy(p => new {p.PersonId, p.FavoriteColor} )
  .Select(g => g.First())
  .ToList();

Example 3: c# distinct comparer multiple properties

public static IEnumerable<TSource> DistinctBy<TSource, TKey>
    (this IEnumerable<TSource> source, Func<TSource, TKey> keySelector)
{
    HashSet<TKey> seenKeys = new HashSet<TKey>();
    foreach (TSource element in source)
    {
        if (seenKeys.Add(keySelector(element)))
        {
            yield return element;
        }
    }
}

Example 4: c# get distinct values all fields from list

if (!IsPostBack) {  
       GridView1.DataSource = GetProducts()
                              .GroupBy(o => new { o.Make, o.Model })
                              .Select(o => o.FirstOrDefault());
       GridView1.DataBind();
}