我正在尝试使用 etag 来缓存我的图像，第一次它应该下载所有图像，但是第二次它也应该使用 304 进入失败的块。
我已经尝试在外部提出请求，但我得到了 304，只是我遇到了 AFNetworking 问题
NSString *urlString = [API_BASE_URL_PHOTOS stringByAppendingPathComponent:[photo getPathToPhoto]];
NSString *properlyEscapedURL = [urlString stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
NSURL *url = [NSURL URLWithString:properlyEscapedURL];
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];
if ([UserDefaultManager getEtagForKey:photo.nom] != nil) {
[request setValue:[UserDefaultManager getEtagForKey:photo.nom] forHTTPHeaderField:ETAG_IF_NONE_MATCH];
}
[request setHTTPMethod:API_METHOD_GET];
AFImageRequestOperation *operation = [AFImageRequestOperation imageRequestOperationWithRequest:request imageProcessingBlock:nil
success:^(NSURLRequest *request, NSHTTPURLResponse *response, UIImage *image) {
[FileUtils createDirectoryInDocumentsWithFileName:photo.folderName];
NSString *docPath = [FileUtils getPathInDocumentsWithFileName:[photo getPathToPhoto]];
// Save Image
NSData *imageData = UIImageJPEGRepresentation(image, 90);
[imageData writeToFile:docPath atomically:YES];
if ([response respondsToSelector:@selector(allHeaderFields)]) {
NSDictionary *allHeaderFields = [response allHeaderFields];
[UserDefaultManager setEtag:[allHeaderFields objectForKey:ETAG] forKey:photo.nom];
}
if ([[DownloadManager sharedManager].downloadQueue.operations count] == 0) {
[[NSNotificationCenter defaultCenter] postNotificationName:NOTIFICATION_DOWNLOAD_ALL_PHOTOS_FINISHED object:nil];
}
}
failure:^(NSURLRequest *request, NSHTTPURLResponse *response, NSError *error) {
if (response.statusCode != RESPONSE_CODE_PHOTO_UP_TO_DATE) {
LogDebug(@"%@", [error localizedDescription]);
}
}];