一),'libxml/tree.h' file not found
Solution:
1. 导入libxml2.dylib 包
2.设置Header Search Paths 为 /usr/include/libxml2
二) reason: -[UIKBBlurredKeyView candidateList]: unrecognized selector sent to instance
三）
*** Terminating app due to uncaught exception 'UIApplicationInvalidInterfaceOrientation', reason: 'Supported orientations has no common orientation with the application, and [UIAlertController shouldAutorotate] is returning YES'