ARC with ASIHTTPRequest

I'm using iOS SDK 5 to develop apps and I'm trying to use ARC. But I need to use ASIHTTPRequest and 开发者_如何学JAVAit's not ARC-enabled. Apple's doc said it's OK to use ARC file-based. So I compile all ASIHTTPRequest files with -fno-objc-arc. I write the following code in my class, which is using ARC:

NSURL *url = [[NSURL alloc] initWithString:urlStr];
ASIHTTPRequest *req = [[ASIHTTPRequest alloc] initWithURL:url];
req.delegate = self;
[req startAsynchronous];

but after executing the first line, the url is nil. What's wrong or how to use manually managed code in ARC project? Thanks.

---

Have you escaped all the not ASCII characters in your URL String? If not, the NSURL instance isn't being created because it doesn't know how to handle the non-ASCII characters in your URL String. You'd need to do something like so:

NSURL *url = [NSURL URLWithString:[urlStr stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]];

Also, Instead of creating your own instance of NSURL, why not use Apple's helper method URLWithString: which will give you an 'autoreleased' NSURL instance like so:

NSURL *url = [NSURL URLWithString:[urlStr stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]];
ASIHTTPRequest *req = [[ASIHTTPRequest alloc] initWithURL:url];
req.delegate = self;
[req startAsynchronous];