public class Album {
    public List<Photo> Photos { get; set; }
}

public class Photo {
    public string Name { get; set; }
}

List<Album> albums = new List<Album>();
albums.Add(new Album {
    Photos = new List<Photo> { 
    new Photo{Name ="Photo1"},
    new Photo{Name ="Photo2"}
}});

albums.Add(new Album {
    Photos = new List<Photo> { 
    new Photo{Name ="Photo3"},
    new Photo{Name ="Photo4"},
    new Photo{Name ="Photo5"}
}
});

var sample = new List<List<string>>();
sample.Add(new List<string> { "a", "b" });
sample.Add(new List<string> { "c", "d", "e" });

            List<Photo> list = new List<Photo>();
            var vs = from p in albums.Select(x => x.Photos) select p;
            foreach (var v in vs)
            {
                list.AddRange((from p in v select p).ToArray());
            }

------解决方案--------------------

一个selectMany操作而已

------解决方案--------------------
linq处理这些很给力啊
SelectMany(x=>x)，x后面还可以做很多事，例如只取第一个数据等等

------解决方案--------------------
探讨


C# code
 var photolist=albums.SelectMany(x=>x.Photos).ToList();