Use launchimage in assets.xcasets to set the IOS startup page, and a black screen will appear after the startup page. After a long time, I haven’t solved the problem. Try using launchscreen.storyboard to set the startup page.
1. Add pictures to the project
2. Edit the picture information of launchscreen.storyboard,
3. Add the constraint of uiiamview in launchscreen.storyboard