Swift 2 JSON字节数组到UIImage

Question

My IOS app is retrieving a JSON Object containing a field "file" which is an image. This field is encoded by the server in Base 64

JSON Serialization: Optional({
file = "/9j/4AAQSkZJRgABAQAAAQABAAD/........

I would need to load this field in an UIImageView. I tried multiple ways without any success. here is an extract of my code:

        let task = session.dataTaskWithRequest(request, completionHandler: { (data: NSData?, response: NSURLResponse?, error: NSError?) -> Void in
        if (error == nil) {

            let json: AnyObject?
            let imageArray: NSData?
            do{
            try json = NSJSONSerialization.JSONObjectWithData(data!, options: [])
                imageArray = json!["file"] as? NSData
                print("JSON file: \(imageArray)")

            }
        catch
        {
            print("error Serialization")
            return
        }

but imageArray is nil...any idea how I can retrieve this field (Base 64 Byte array) and convert it in an UIImage ?

Answer 1

JSON cannot contain binary data. It can only contain Strings, Numbers, Booleans and Nulls. You need to convert the base64 String to NSData yourself.

Replace the line imageArray = json!["file"] as? NSData imageArray = json!["file"] as? NSData to the following 5 lines.

if let fileBase64 = json!["file"] as? String {
    imageArray = NSData(base64EncodedString: fileBase64, options: [])
} else {
    print("missing `file` entry")
}