Xcode 9 asset catalog Preserves Vector Data not working?

user_341994 0
Viewed 6199

I thought the new Preserves Vector Data checkmark in the Xcode 9 asset catalog would finally give us resizing of vector PDF images, but apparently not. Here's my test image seen at two zooms in Preview:

enter image description here

enter image description here

Nice and sharp with lots of zoom, so clearly this is a vector image. But here's what two image views look like in my app:

enter image description here

So where's my vector data? Is this much-desired feature still missing in action? Does it still work only for the automatically generated 2x and 3x images? And if so, what does the Preserve Vector Data checkbox give us that we didn't have already?

asset-catalog xcode9
4 Answers

I had the same issue multiple times with the new Preserves Vector Data.

Super simple solution that worked very well for me:

  1. Never set the UIImageView image property in Interface Builder, just leave it empty.
  2. Set the image value programmatically.

Hope it helps.

user_5982000

In my case (Xcode 9.4.1), with imageView created in Interface Builder - I noticed that when I initially arrive on the screen, the image is blurry. If I then change device orientation, the image becomes crisp. I tried calling different methods manually in viewDidLoad() and here is what I found so far:

This worked:

let image = imageView.image
imageView.image = nil
imageView.image = image

None of these worked:

imageView.layoutSubviews()
imageView.layoutMarginsDidChange()
imageView.setNeedsLayout()
imageView.setNeedsDisplay()
imageView.reloadInputViews()
imageView.updateConstraints()
imageView.contentMode = .center ; imageView.contentMode = .scaleToFill

You should of course extend or subclass UIImageView if you'll be calling it often, like this for example

class UIImageViewWithPreserveVectorDataFix: UIImageView {
    override func awakeFromNib() {
        super.awakeFromNib()
        let image = self.image
        self.image = nil
        self.image = image
    }
}

(and then of course set UIImageViewWithPreserveVectorDataFix as the class in Interface Builder)

user_16784200
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