iOS全屏图片适应问题

Question

要做一个首页（是首页不是开机页），一个全屏图片作为背景。现在苹果出了很多尺寸的手机，怎样才能自适应屏幕呢。
我想到的方法是，根据不同尺寸的屏幕各做一个背景图片，然后判断是什么尺寸，找到相应的图片。
我想知道有没有方法可以自动适应，我觉得背景图应该还是要每个尺寸一张。不知各位高手怎么看~

Answer 1

The built-in assert can put 2x, 3x pictures, iOS will take different pictures according to various models, 6SPlus will automatically take 3x pictures, and others will take 2x pictures. However, when the 5 and 6 screen sizes are different, they will automatically adapt to the 2x image, and there will inevitably be some problems with the image accuracy. So what I did was put another 5 size picture. Take different pictures according to the situation. Of course, the size of 4 is not considered here.