Bordertown Labs Blog
Notes from Bordertown Labs with posts regarding software development for the iPhone, Ruby on Rails, tips and code.
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Posts tagged "asynchronous"
Sep 20th, 2011 @ 5:38 pm
Using GCD and Blocks Effectively
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_LOW, 0), ^{
NSURL *url = [NSURL URLWithString:@"http://bit.ly/nUX01h"];
NSURLRequest *req = [NSURLRequest requestWithURL:url];
[NSURLConnection sendAsynchronousRequest:req
queue:[NSOperationQueue currentQueue]
completionHandler:
^(NSURLResponse *res, NSData *data, NSError *err) {
// Convert the data to a UIImage
UIImage *image = [UIImage imageWithData:data];
// Scale the image
UIImage *thumbImage = nil;
CGSize newSize = CGSizeMake(90, (90 / image.size.width) * image.size.height);
UIGraphicsBeginImageContext(newSize);
[image drawInRect:CGRectMake(0, 0, newSize.width, newSize.height)];
thumbImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
dispatch_async(dispatch_get_main_queue(), ^{
self.imageView.image = thumbImage;
});
}];
});
