UIImage init with scale in swift says "Extra Argument" Erroneously

Question

OK. This is whacky. I've checked the various answers above, and this is the only one that seems to really hit the mark.

However, there doesn't seem to be an answer.

I am using Swift to create a new UIImage, exactly like this (Objective-C version):

UIImage *myImage = [[UIImage alloc] initWithCGImage: aCGImageRefAllocatedPreviously scale:aCGFloatScaleCalculatedPreviously orientation:UIImageOrientationUp];

That works fine. However, when I try the same exact call in Swift:

let myImage = UIImage ( CGImage: aCGImageAllocatedPreviously, scale:aCGFloatScaleCalculatedPreviously, orientation:UIImageOrientation.Up )

I get a compiler error, telling me that "scale" is an extra parameter.

This is the kind of error that you get when the signature is wrong.

However, it isn't wrong (as far as I can tell).

What I am doing, is creating a tutorial by exactly replicating an Objective-C function in Swift (I know, I know, Swift is different, so I shouldn't exactly replicate, but, as Bill Murray would say, "Baby Steps").

I'm wondering how the heck I'm screwing up.

If I call it with just the image (no scale or orientation), it works fine, but I need that scale.

Are you sure aCGImageRefAllocatedPreviously is type of CGImage? If not then compiler may give you that error. — Abdullah, Mar 26 '15 at 13:32
The `aCGFloatScaleCalculatedPreviously` variable could be an issue as well, if it were actually a Double for example. — Mick MacCallum, Mar 26 '15 at 13:37
Yeah, that's because I didn't copy and paste properly. However, I figgered it out. — Chris Marshall, Mar 26 '15 at 13:39
I needed to use takeRetainedValue() on the input CGImage. In my other implementation, I had done that prior, and I missed it. — Chris Marshall, Mar 26 '15 at 13:40
... which again demonstrates how useful a (small) self-contained reproducible example would be ... — Martin R, Mar 26 '15 at 13:43
Whatever. I'm doing my best. I can't paste the whole thing for a number of reasons, one being that I'd get fired if I did. — Chris Marshall, Mar 26 '15 at 15:15

score 1 · Answer 1 · answered Mar 26 '15 at 13:42

I tried this in the playground and was able to get this code to compile:

import UIKit
import AVFoundation

let myImage = UIImage(CGImage: nil,
  scale:0,
  orientation:UIImageOrientation.Up)

This syntax also works:

let newImage = UIImage.init(CGImage: nil,
  scale:0,
  orientation:UIImageOrientation.Up )

Chris Marshall · Accepted Answer · 2015-03-26T15:13:27.300

0

OK. I figgered it out. I was a knucklehead.

I need to use takeRetainedValue() on the CGImage, like so:

let myImage = UIImage ( CGImage: aCGImageAllocatedPreviously.takeRetainedValue(),scale:aCGFloatScaleCalculatedPreviously,orientation:UIImageOrientation.Up )

That satisfies the signature.

edited Mar 26 '15 at 15:13

answered Mar 26 '15 at 13:45

Chris Marshall

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Is it takeRetainedImage() or takeRetainedValue()? – I assume the latter. Please do copy/paste the real code in your question and answers. Otherwise you are wasting your time and that of the readers. – Martin R Mar 26 '15 at 13:49
@Martin R Good point. The problem is that I am working on a work machine that has no internet connection, and turning around and working on this laptop, so stuff is getting lost in translation. I'll fix it. No, it's not wasting time. It's called "legitimate error," and we all do it. I appreciate it being pointed out. – Chris Marshall Mar 26 '15 at 15:13

UIImage init with scale in swift says "Extra Argument" Erroneously

2 Answers2