Concatenate collection from property
class oA { int type; List<oB> list; } class oB { int id, decimal price, string name } somewhere you get a list from oA objects.
What is the correct way to have 1 list of oB objects from all the oA objects of a certain type?
i was thinking something like this
var myoAs = new List<oA>(); /* Load data from wherever */ var myList = myoAs.Where(x => x.type == 1).select(....) Who knows the anwer how to get a complete list of all the oB objects (and even remove duplicates in the linq as well if possible)
Use SelectMany to aggregate multiple lists and Distinct to filter duplicates.
var myList = myoAs.Where(x => x.type == 1).SelectMany(a => a.list).Distinct(); 
You can use this extension method
IEnumerable distinctList = myoAs.SelectMany(x=>x.list).DistinctBy(x => x.name);
public static IEnumerable<TSource> DistinctBy<TSource, TKey>( this IEnumerable<TSource> source, Func<TSource, TKey> keySelector) { var knownKeys = new HashSet<TKey>(); return source.Where(element => knownKeys.Add(keySelector(element))); } 
