iOS 应用的启动页必须使用png图片

今天提交应用，被打回来了，邮件描述以下:

iPhone 5 Optimization Requirement  - Your binary is not optimized for iPhone 5. New iPhone apps and app updates submitted targeting iOS 6 and above must support the 4-inch display on iPhone 5 and must include a launch image with the -568h size modifier immediately following the <basename> portion of the launch image's filename. Launch images must be PNG files and located at the top-level of your bundle, or provided within each .lproj folder if you localize your launch images. Learn more about iPhone 5 support and app launch images by reviewing the  iOS Human Interface Guidelines  and  iOS App Programming Guide .

主要缘由是没有使用png的图片做为启动页，一直以来Apple都要求用png的图片来做为启动页，可是png相对于jpg来讲要大多了，为了减小应用体积，之前的作法是能够经过info.plist的设置来使用jpg的:

如今这种方法已经失效了，编译的时候和之前同样，都是顺利经过的，但当你打包应用，上传到iTunes Connect后，Apple会再次检查，这时候就会被发现没有使用png图片做为启动页，提示Invalid Binary，并经过邮件通知你。

因此，最后仍是要老老实实地按照Apple的要求，使用png图片做为启动页…