Question

i got a generic list that looks like this:

List<PicInfo> pi = new List<PicInfo>();

PicInfo is a class that looks like this:

[ProtoContract]
public class PicInfo
{
        [ProtoMember(1)]
        public string fileName { get; set; }
        [ProtoMember(2)]
        public string completeFileName { get; set; }
        [ProtoMember(3)]
        public string filePath { get; set; }
        [ProtoMember(4)]
        public byte[] hashValue { get; set; }

        public PicInfo() { } 
}

what i’m trying to do is:

• first, filter the list with duplicate file names and return the duplicate objects;
• than, filter the returned list with duplicate hash value’s;

i can only find examples on how to do this which return anonymous types. but i need it to be a generic list.

if someone can help me out, I’d appreciate it. also please explain your code. it’s a learning process for me.

thanks in advance!

[EDIT]

the generic list contains a list of objects. these objects are pictures. every picture has a file name, hash value (and some more data which is irrelevant at this point). some pictures have the same name (duplicate file names). and i want to get a list of the duplicate file names from this generic list ‘pi’.

But those pictures also have a hash value. from the file names that are identical, i want another list of those identical files names that also have identical hash values.

[/EDIT]

Answer 1

I think, you have to use SequenceEqual method for finding dublicate
(http://msdn.microsoft.com/ru-ru/library/bb348567.aspx).
For filter use