前天使用最新版的Xamarin Forms 4.4提交应用后，今天Apple审核返回信息如下：
Guideline 2.5.1 – Performance – Software Requirements

Your app uses or references the following non-public APIs:
– LinkPresentation.framework
– QuickLookThumbnailing.framework
The use of non-public APIs is not permitted on the App Store because it can lead to a poor user experience should these APIs change.
Continuing to use or conceal non-public APIs in future submissions of this app may result in the termination of your Apple Developer account, as well as removal of all associated apps from the App Store.
Next Steps
If you are using third-party libraries, please update to the most recent version of those libraries. If you do not have access to the libraries’ source, you may be able to search the compiled binary using the “strings” or “otool” command line tools. The “strings” tool can output a list of the methods that the library calls and “otool -ov” will output the Objective-C class structures and their defined methods. These tools can help you narrow down where the problematic code resides. You could also use the “nm” tool to verify if any third-party libraries are calling these APIs.

今天我来介绍一下XNA的另一个开源实现FNA。FNA与MonoGame的区别在于：FNA的跨平台是基于运行库的而MonoGame的跨平台是基于源码的，也就是说理论上FNA编译好的游戏不需要修改源码就可以运行在不同的硬件平台，而MonoGame需要将源码放到指定平台重新编译才能运行。