Code=3072 "The operation was cancelled" when setting alternate app icon - ios

Question

I am trying to set an alternate app icon named MyIcon in my iOS app. I have a MyIcon.png image in my project bundle (not in my Assets folder) and it is declared in my Info.plist like so:
<key>CFBundleIcons</key>
<dict>
<key>CFBundleAlternateIcons</key>
<dict>
<key>MyIcon</key>
<dict>
<key>CFBundleIconFiles</key>
<array>
<string>MyIcon</string>
</array>
<key>UIPrerenderedIcon</key>
<false/>
</dict>
</dict>
</dict>
In my code, I try to change the app icon:
UIApplication.shared.setAlternateIconName("MyIcon")
However, the icon doesn't change and I am instead given this error in the console:
Error Domain=NSCocoaErrorDomain Code=3072 "The operation was cancelled."
How can I fix this issue?

Answer 1

I was getting this error because of two reasons,
First(and highly not because of), I didn't do "Add Files to 'ProjectNameFoo'" by adding png file to project. Otherwise it didn't work. After that it started to see icon.
Secondly(and highly possible reason), I was getting this error because I was trying to change the icon in viewDidLoad. When I try with a delay like the code below it was working whatever second I gave.
override func viewDidLoad() {
super.viewDidLoad()
DispatchQueue.main.asyncAfter(deadline: .now() + 1) {
UIApplication.shared.setAlternateIconName("MyIcon")
}
}

Answer 2

I was stuck with this error for quite a while and tried all sorts of things but couldn't work out what I was doing wrong. I was changing the icon from AppDelegate.application(didFinishLaunchingWithOptions:). Delaying the call with a timer as suggested above did solve it.
It is worth noting that this problem is due to UIKit trying to show a UIAlertController with the message
You have changed the icon for $(PRODUCT_NAME)
and that didn't seem to work at that point. You need to wait until a root view controller is loaded.
This is because this API is not meant to for the developer to update the icon arbitrarily, but for the user to deliverability choose one.