我需要下载带有进度条的图像。这就是我在 AFNetworking 1.x 中所做的，它不适用于 AFNetworking 3.x。
NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:self.mediaItem.media_item_hd_url]];
AFHTTPRequestOperation *op = [[AFHTTPRequestOperation alloc] initWithRequest:request];
op.responseSerializer = [AFImageResponseSerializer serializer];
[op setCompletionBlockWithSuccess:^(AFHTTPRequestOperation *operation, id responseObject) {
UIImage *image = responseObject;
_image = image;
[self.delegate browserItem:self loaded:1.0 finished:YES];
} failure:^(AFHTTPRequestOperation *operation, NSError *error) { }];
[op setDownloadProgressBlock:^(NSUInteger bytesRead, long long totalBytesRead, long long totalBytesExpectedToRead) {
CGFloat progress = ((CGFloat)totalBytesRead)/((CGFloat)totalBytesExpectedToRead);
[self.delegate browserItem:self loaded:progress finished:NO];
}];
[[NSOperationQueue mainQueue] addOperation:op];
最后，这是我能想到的，但并不完整。我不知道如何在代码块中使用进度。
NSURLSessionConfiguration *configuration = [NSURLSessionConfiguration defaultSessionConfiguration];
AFURLSessionManager *manager = [[AFURLSessionManager alloc] initWithSessionConfiguration:configuration];
NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:self.mediaItem.media_item_hd_url]];
NSURLSessionDownloadTask *downloadTask = [manager downloadTaskWithRequest:request progress:nil destination:^NSURL *(NSURL *targetPath, NSURLResponse *response) {
NSURL *documentsDirectoryURL = [[NSFileManager defaultManager] URLForDirectory:NSDocumentDirectory inDomain:NSUserDomainMask appropriateForURL:nil create:NO error:nil];
return [documentsDirectoryURL URLByAppendingPathComponent:[response suggestedFilename]];
} completionHandler:^(NSURLResponse *response, NSURL *filePath, NSError *error) {
NSLog(@"File downloaded to: %@", filePath);
// UIImage *image = response;
// _image = image;
[self.delegate browserItem:self loaded:1.0 finished:YES];
}];
[downloadTask resume];