image_manager_disk_cache可删。image_manager_disk_cache是可以删除的，用户删除以后，能够清理出不少的内存，删除错误的情况下还可以根据需要从备份还原。
To download an image, you only have to use the following method from LRImageManager: - (void)imageFromURL:(NSURL*)url size:(CGSize)size cacheStorageOptions:(LRCacheStorageOptions)cacheStorageOptions completionHandler:(LRImageCompletionHandler)completionHandler; ...
DownLoadManager[20530:228829] DiskImageCache: Could not resolve the absolute path of the old directory. 但是在真机调试是正常的。