ios - swift tabbar图片填充问题

Question

已有：图片上面本来没有字，我设定的title

1.如何用代码调整图片的填充
2.是不是图片太大了
如果自定义应该怎么实现 代码

Answer 1

Adjust the corresponding image size to a suitable size. For Retina display, note that the image name suffix is ​​increased by @2x @3x.

For specific sizes, please refer to: https://developer.apple.com/library/ios/documentation/UserExperience/Conceptual/MobileHIG/IconMatrix.html