圖片適配
1.選擇Assets.xcassets—>左下角+號—>New Image Set.然后自己命一個名字

2.修改圖片的Contents.json文件,修改內(nèi)容如下(雙擊圖片,選擇Show in Finder,文件夾里面有一個Contents.json文件,雙擊打開)
{"images":[{"idiom":"iphone","scale":"1x"},{"idiom":"iphone","scale":"2x"},{"idiom":"iphone","scale":"3x"},{"idiom":"iphone","scale":"1x","subtype":"retina4"},{"idiom":"iphone","scale":"2x","subtype":"retina4"},{"idiom":"iphone","scale":"3x","subtype":"retina4"},{"idiom":"iphone","scale":"3x","subtype":"736h"},{"idiom":"iphone","scale":"2x","subtype":"667h"},{"idiom":"iphone","scale":"3x","subtype":"2436h"},{"idiom":"iphone","scale":"3x","subtype":"2688h"},{"idiom":"iphone","scale":"2x","subtype":"1792h"}],"info":{"author":"xcode","version":1}}
3.此時就可以根據(jù)不同屏幕適配不同的啟動圖了

4.適配完各個屏幕圖片后,去LaunchScreen.storyboard搭建啟動圖
