code: public void preLoadImages(String[] urls) {
          int len = urls.length;
          for (int i = 0; i < len; i++) {
              ImageLoadRequest request = new ImageLoadRequest(urls[i]);
              final ImageTask imageTask = createImageTask(request);
              imageTask.setIsPreLoad();
              addImageTask(imageTask, null);
          }
      }
docs: Load the image in advance.