App提交到App Store时警告如下：
WARNING ITMS-90737: "Missing Document Configuration. By declaring the CFBundleDocumentTypes key in your app, you've indicated that your app is able to open documents. Please set the UISupportsDocumentBrowser key to "YES" if your app uses a UIDocumentBrowserViewController. Otherwise, set the LSSupportsOpeningDocumentsInPlace key in the Info.plist to "YES" (recommended) or "NO" to specify whether the app can open files in place. All document-based apps must include one of these configurations. For more information, visit https://developer.apple.com/document-based-apps/."
解决方法：
- 在Info.plist中添加UISupportsDocumentBrowser并设置为YES