public void PictureUpdated(PictureInfo picture)
 {
     lock (this.Lock)
     {
         this.list.Sort(this.comparer);
     }
 }
 public void SortedInsert(PictureInfo picture)
 {
     lock (this.Lock)
     {
         int index = this.list.BinarySearch(picture, this.comparer);
         if (index < 0)
         {
             this.list.Insert(~index, picture);
             picture.PictureUpdated += this.PictureUpdated;
         }
     }
 }