public void Cancel() { idle_start.Stop(); step.Stop(); if (importer != null) { importer.Cancel(); importer = null; } if (collection == null || collection.Count == 0) { return; } Photo [] photos = new Photo [collection.Count]; for (int i = 0; i < collection.Count; i++) { photos [i] = (Photo)collection [i]; } store.Remove(photos); }