XCode 8 不正确的背景颜色 - 故事板更新的色彩空间

Question

After upgrading to XCode 8, I noticed some of my views (layed out in Interface Builder) now have incorrect colors.

Specifically, I have two custom views on my login page which normally have a white background. After upgrading to XCode 8, their background color is clear! Looks terrible.

I've done some investigation and found this from Apple:

Color values in Interface Builder documents correctly use color space during rendering and compilation. Earlier versions of Xcode mishandled color spaces saved in iOS and tvOS documents. Xcode 8 converts existing colors in a way that preserves their perceptual appearance on device, and updates either the color space or component values in the source document as appropriate. (7645087)

And sure enough, when I look at the diff for the commit that broke things:

This:

<rect key="frame" x="8" y="8" width="88" height="48"/>
<color key="backgroundColor" white="0.0" alpha="0.0" colorSpace="calibratedWhite"/>

Was replaced by this:

<color key="backgroundColor" red="0.0" green="0.0" blue="0.0" alpha="0.0" colorSpace="custom" customColorSpace="sRGB"/>

What can I do to fix this? Here are some things I have tried:

1) Within interface builder, select the view, and open the color pallet for background color. Click the gear icon, and select SRGB. Tried other profiles as well, nothing seems to work.

2) Tried reverting the XIB file. Can't do this since it was part of XCode 8 upgrade. This change to the color profiles happens when you call "Update Frames" for the view controller, after selecting the iPhone size you want.

Anyone have any other suggestions would be so helpful!

Answer 1

Incredible.

In my custom view (subclass of UIView), I had a "commonInit" method, which held all of the common instantiation code called via "init", "initWithCoder:" or "initWithFrame:"

Within that "commonInit" method, I was doing something I probably shouldn't have been doing:

self.layer.cornerRadius = 0.5 * self.bounds.size.height;

Somehow, this worked on iOS 9.3 + XCode 7, but NOT IOS10 + XCode 8

It makes sense why it shouldn't work. At time of instantiation, the view hasn't yet been layed out, and so it's frame is likely {0,0,0,0}.

The solution was to move that code into "layoutSubviews".

The question remains as to why the behavior resulted in a clear background. Probably, because a cornerRadius of 0 is not supported?

Answer 2

I've had the same problem about custom views (the background color can't be set). With some searching and trial and error, my problem has been resolved. The tips to resolve the problem are:

1. when you open xib, there will show a notice to "choose an initial device view", and there will be two options; you can choose the "choose Device".

2. find out "interface builder Document" in the right sidebars and reset the "open in" to be Xcode 7.x. After setting that there will be a notice to save your settings; you should choose "save and close".

Following these steps may resolve your issue.