为什么imageData会在swift 3中返回nil？

Question

嗨我想将图像转换为数据，但问题是数据将返回nil 我想用Alamofire上传图片所以我需要在使用Alamofire之前转换图像这里是我的代码

let imageData = UIImageJPEGRepresentation(ViewController.imageUpload[i], 1.0)


            Alamofire.upload(imageData! , to: "http://example.com/api/file?api_token=\(api_token)&id=\(postID)").responseJSON { response in
                debugPrint(response)
            }

Answer 1

尝试下面的代码来获取imageData，并确保你传递的图像不是nil，

对于PNG： -

let data = UIImagePNGRepresentation(ViewController.imageUpload[i]) as NSData?

对于JPEG： -

let data = UIImageJPEGRepresentation(ViewController.imageUpload[i], 1.0) as NSData?

并且还要在保存时检查您正在使用的图像扩展名（PNG或JPEG）

要了解图片扩展程序，请查看以下代码，

func imagePickerController(picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : AnyObject]) {
        if (!(picker.sourceType == UIImagePickerControllerSourceType.Camera)) {
            let assetPath = info[UIImagePickerControllerReferenceURL] as! NSURL
            if assetPath.absoluteString.hasSuffix("JPG") {
            }
        }
    }