Recently I’ve faced a weird bug about displaying image from URL to UIImageView. Finally I found out is the header issue.

Let’s take an example, there are 2 images

Image1 has the header

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HTTP 200 No Error

Server: AmazonS3
Content-Type: binary/octet-stream
Last-Modified: Mon, 01 Jul 2013 03:06:03 GMT
x-amz-meta-type: image/jpeg
x-amz-request-id: 8845F67C90997FF6
Date: Fri, 15 Nov 2013 04:02:30 GMT
x-amz-id-2: F9crPjTya1RNjUeaNLkE2cQTOet8WnAk72idgXeXBIglwwxHLVBvWbL67IC4Brkm
Accept-Ranges: bytes
Content-Length: 127456
Etag: "545ccc75ee7fc045ed201092742af52e"

Image2 has the header

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HTTP 200 No Error

Server: Microsoft-IIS/8.0
Content-Type: image/jpeg
X-Powered-By: ASP.NET
Last-Modified: Thu, 24 Oct 2013 21:41:42 GMT
Accept-Ranges: bytes
Date: Fri, 15 Nov 2013 04:07:30 GMT
Content-Length: 60585
Etag: "16e91dd41d1ce1:0"

Look at the Content-Type, Image1 with the Content-Type binary/octet-stream (if you type the URL in browser it will force download), while Content-Type of Image2 is image/jpeg (it will display in browser if you type in the URL).

Solution

I make a plain HTTP request

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NSString *url = @"http://example.com/image1.jpg";
AFHTTPClient *httpClient = [[AFHTTPClient alloc] initWithBaseURL:[NSURL URLWithString:url]];
[httpClient setParameterEncoding:AFFormURLParameterEncoding];

NSURLRequest *request = [httpClient requestWithMethod:@"GET"
                                                 path:url
                                           parameters:nil];

AFHTTPRequestOperation *operation = [[AFHTTPRequestOperation alloc] initWithRequest:request];
[operation setCompletionBlockWithSuccess:^(AFHTTPRequestOperation *operation, id responseObject) {
    UIImage *image = [UIImage imageWithData:responseObject];
    imageView.image = image;
} failure:^(AFHTTPRequestOperation *operation, NSError *error) {
    NSLog(@"Error: %@", error.description);
}];
[operation start];

instead of (this will only work for Content-Type: image/jpeg)

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NSString *url = @"http://example.com/image1.jpg";
[[AFImageRequestOperation imageRequestOperationWithRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:url]] success:^(UIImage *image) {
    imageView.image = image;
}] start];