Swift:Use AFNetworking setImageWithURL
From Hawk Wiki
Create the bridging file: create a new Objective-C file, name it anything, and when you save it, Xcode will prompt you generate a bridging file.
In an Objective-C bridging file:
#import <AFNetworking/UIImageView+AFNetworking.h>
In the swift view file, to set a imageView using URL:
setImageWithURL(NSURL(string: thumbnailURL))