SDWebImage YYImage 加载图片失败

http://img5.imgtn.bdimg.com/it/u=3017210771,879699792&fm=11&gp=0.jpg

http://img5.imgtn.bdimg.com/it/u=3017210771,879699792&fm=11&gp=0.jpg

我们用SDWebImage或者YYImage加载上述url的网络图片时会发现根本无法加载，但是浏览器能够读取出来，甚至安卓端也能够读取出来，为什么iOS端就无法读取呢，原因是因为要设置User-Agent

SDWebImage:

[[SDWebImageDownloader sharedDownloader] setValue:@"iPhone" forHTTPHeaderField:@"User-Agent"];

YYImage:

    NSMutableDictionary *header = [YYWebImageManager sharedManager].headers.mutableCopy;
    header[@"User-Agent"] = @"iPhone"; // for example
    [YYWebImageManager sharedManager].headers = header;