Canceling a ASIHTTPRequest - Beginner - iphone

Question

I am using ASIHTTPRequest to send request to web server. It all works fine. But now, when i call the grabURLInBackground method, a request is sent to the given URL.
But now, i need to cancel the request (as in stop sending, and stop downloading the content from the URL), in the viewWillDissapear method. How can i do this ? Help
- (IBAction)grabURLInBackground:(id)sender
{
NSURL *url = [NSURL URLWithString:#"http://allseeing-i.com"];
ASIHTTPRequest *request = [ASIHTTPRequest requestWithURL:url];
[request setDelegate:self];
[request startAsynchronous];
}
- (void)requestFinished:(ASIHTTPRequest *)request
{
// Use when fetching text data
NSString *responseString = [request responseString];
// Use when fetching binary data
NSData *responseData = [request responseData];
}
- (void)requestFailed:(ASIHTTPRequest *)request
{
NSError *error = [request error];
}

Answer 1

for (ASIHTTPRequest *req in ASIHTTPRequest.sharedQueue.operations)
{
[req cancel];
[req setDelegate:nil];
}
this should cancel it..

Answer 2

You can do:
[request cancel]
Or:
[request clearDelegatesAndCancel];
As can be seen in the documentation here.
I'd suggest storing a reference to that request so you can cancel it when leaving the view.

Answer 3

GOt thsi from ASIHttp docs:
Cancelling an asynchronous request
To cancel an asynchronous request (either a request that was started with [request startAsynchronous] or a request running in a queue you created), call [request cancel]. Note that you cannot cancel a synchronous request.
Note that when you cancel a request, the request will treat that as an error, and will call your delegate and/or queue’s failure delegate method. If you do not want this behaviour, set your delegate to nil before calling cancel, or use the clearDelegatesAndCancel method instead.
// Cancels an asynchronous request
[request cancel]
// Cancels an asynchronous request,
clearing all delegates and blocks first
[request clearDelegatesAndCancel];When using an ASINetworkQueue, all other requests will be cancelled when you cancel an individual request unless the queue’s shouldCancelAllRequestsOnFailure is NO (YES is the default).
// When a request in this queue fails or is cancelled, other requests will continue to run
[queue setShouldCancelAllRequestsOnFailure:NO];
// Cancel all requests in a queue
[queue cancelAllOperations];