Xcode7 Low-version iOS system with black edge problem

When developing with Xcode7, the default startup page is changed to Launch screen storyboard. Usually it is customary to use Launchimage, the introduction under Xcode7 How to change to start page is launchimage.

1:project->target->general->app Icons and Launch images the Launch screen File below is changed to null (default is Launchscreen.storyboard)

2: Click Launchscreen.storyboard, click on the right side, use as Launch screen tick off

3: Click Assets.xcassets, right-click->app Icons & Launch images->new IOS Launch Image, so that there is a Launchimage collection, Put the start page picture in the corresponding area respectively

4:project->target->general->app Icons and Launch Images below Launch Images Source changed to Launchimage

Xcode7 Low-version iOS system with black edge problem