Let's look at two pictures first.
1,
2,
When this happened I was scared to pee, and then I used my own cell phone to test the (iOS10.2.1), and did not find such problems, and then take a colleague mobile phone test (iOS11.2.1), also did not appear such problems.
Your own tests are not measurable. Then ask the marketing staff, according to the market staff to know about the customer's mobile phone information is: The IPhone 6 iOS8.1.1, and then immediately ran the simulator with the simulation that there is such a phenomenon.
And then went online to search for some posts, and through the test found that this is Xcode problem
Solving Method
1, wait for Apple Dad fix Xcode bug (already have the big God to Apple Father submitted a question, as for the next Xcode version repair not only the fate)
2, do not use assets to manage the picture, pull out the picture, placed in a separate folder can be resolved
3, downgrade the Xcode version, do not use Xcode version 9.2
4, improve the compatibility of the system version of the project (minimum Fit with 9.0)
5, let the customer upgrade mobile phone system version
Reprinted from http://blog.csdn.net/kun__kun/article/details/79087668