在iOS上生成随机默认屏幕
Xcode中的一个先决条件是设置iPhone应用程序加载时的默认和默认@ 2x图像。
One of the prerequisites within Xcode is setting the 'Default' and 'Default@2x' images for when the iPhone app loads up.
是否可以有多个默认屏幕，以png格式插入到项目中，每次加载应用程序时，选择一个随机默认屏幕使用？
Is it all possible to have a number of Default screens made, inserted into the project in png format and each time the app is loaded, choose a random default screen to use?
您无法更改Default.png。一旦应用程序发货 - 它就是一成不变。直到下一个版本，就是这样。原因很简单（同样为什么你不能改变应用程序图标）。 App的捆绑包是只读的。它是只读的，因为它是由你和苹果签署的。修改捆绑包的内容会使签名无效。
You cannot change Default.png. Once the app is shipped - it's "set in stone". Until the next release, that is. The reason is simple (and same why you can't change apps icon). App's bundle is read-only. It is made read only because it is signed by you and by apple. Modifying the contents of the bundle would invalidate the signature.