清空图片缓存

// 清理内存[[SDImageCache sharedImageCache] clearMemory];// 清理webview 缓存NSHTTPCookieStorage*storage = [NSHTTPCookieStoragesharedHTTPCookieStorage];for(NSHTTPCookie*cookiein[storage cookies]) {    [storage deleteCookie:cookie];}NSURLSessionConfiguration*config = [NSURLSessionConfigurationdefaultSessionConfiguration];[config.URLCache removeAllCachedResponses];[[NSURLCachesharedURLCache] removeAllCachedResponses];// 清理硬盘[[SDImageCache sharedImageCache] clearDiskOnCompletion:^{    [MBProgressHUD hideAllHUDsForView:self.view animated:YES];    [self.tableView reloadData];}];