Question

I tried to display an image returned by Google Chart API, but the codes below do not work:

NSData *imageData = [NSData dataWithContentsOfURL:[NSURL URLWithString:@"http://chart.apis.google.com/chart?cht=p3&chd=t:60,40&chs=250x100&chl=Hello|World"]];
UIImage *downloadedImage = [UIImage imageWithData:imageData];
imgView.image = downloadedImage;

or

NSData *imageData=[NSURLConnection sendSynchronousRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:@"http://chart.apis.google.com/chart?cht=p3&chd=t:60,40&chs=250x100&chl=Hello|World"]] returningResponse:nil error:nil];
UIImage *downloadedImage = [UIImage imageWithData:imageData];
imgView.image = downloadedImage;

The target image was not shown as expected. Do you have any idea where the problem was?

Answer 1

Both pieces of code work, except the NSURL object is nil. NSURL does not support pipe characters (|), so you need to escape it with %7c. You could use [NSString stringByAddingPercentEscapesUsingEncoding:] to take care of any other characters. Here is the new version:

NSString *url = [@"http://chart.apis.google.com/chart?cht=p3&chd=t:60,40&chs=250x100&chl=Hello|World" stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
NSData *imageData = [NSData dataWithContentsOfURL:[NSURL URLWithString:url]];
UIImage *downloadedImage = [UIImage imageWithData:imageData];
imgView.image = downloadedImage;