问题
When I send a synchronous request with NSURLConncetion
[NSURLConnection initWithRequest:myRequest delegate:self];
I can receive my downloaded data in pieces with the following method
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data {
[self.videoData appendData:data];
NSLog(@"APPENDING DATA %@",data);
}
The advantage of this is that I can write my data directly to a file, and limit ram usage when downloading large files.
When I send an asynchronous request, how can I receive my data in pieces? The only place I see the data given back to me is in the completion handler of the request.
[NSURLConnection sendAsynchronousRequest:videoRequest
queue:downloadQueue
completionHandler:^(NSURLResponse* response, NSData* data, NSError* error){
NSLog(@"All data is given here!");
}];
Is there any solution to this problem? I'm downloading large files in a view controller and want to continue downloading them if the view controller gets dismissed. The problem is that I'm going to use too much memory if I receive all my data at once when downloading large files.
回答1:
The only method in NSURLConnection which is synchronous is + sendSynchronousRequest:returningResponse:error:
The following methods are all asynchronous
+ connectionWithRequest:delegate:
– initWithRequest:delegate:
– initWithRequest:delegate:startImmediately:
+ sendAsynchronousRequest:queue:completionHandler:
– start
So the code [NSURLConnection initWithRequest:myRequest delegate:self]; itself is an asynchronous, You can use it as it is.
OR
You can make use of NSURLSession for more control
NSURLSessionConfiguration *configuration = [NSURLSessionConfiguration defaultSessionConfiguration];
NSURLSession *session = [NSURLSession sessionWithConfiguration:configuration delegate:self delegateQueue:nil];
self.downloadTask = [self.session downloadTaskWithRequest:request];
[self.downloadTask resume];
- (void)URLSession:(NSURLSession *)session downloadTask:(NSURLSessionDownloadTask *)downloadTask didWriteData:(int64_t)bytesWritten totalBytesWritten:(int64_t)totalBytesWritten totalBytesExpectedToWrite:(int64_t)totalBytesExpectedToWrite {
}
来源：https://stackoverflow.com/questions/24857919/how-can-i-receive-my-data-in-pieces-with-using-nsurlconnections-sendasynchronou