前言

由于工作需求，在项目中导入Unity。在使用到Vuforia展示AR的时候，遇到了相机黑屏的情况，最终在Vuforia官网找到了解决方案。
解决Vuforia 7 / iOS 11.3黑屏问题？

问题原因

按照官方的解释就是，苹果这个傻B在搞事情，我们会尽快提供一个补丁。

With ARKit 1.5 beta, we found early on that Apple significantly broke our integration. However, due to the known timing of our 7.1 release and the unknown timing of iOS 11.3, we (blindly) moved forward with fixing the issue in our 7.2 release. Now that iOS 11.3 has officially release, we have escalated the need for a patch and it is currently underway.

解决方案

在Apple Developer上下载Xcode 9.2;

1. 点击Downloads；
2. 滑动到底端，点击See more downloads；
   
3. 找到Xcode 9.2，点击蓝字进行下载。

将DeviceSupport 11.3添加到Xcode 9.2中；

1. 从网上下载DevieSupport 11.3；
2. 或者从Xcode 9.3中导出，右键点击Xcode 9.3->显示包内容->Contents->Developer->Platforms->iPhoneOS.platform->DeviceSupport，把11.3复制；
3. 将上面复制的DeviceSupport 11.3添加到Xcode 9.2中，路径同2。

重启Xcode 9.2，打开Unity导出的Xcode工程，至此，大功告成！