我正在尝试实现注册过程，该过程允许我的iOS应用程序显示在其他应用程序的"打开位置"列表中（如Apple的文档交互编程主题中所述）。我希望我的应用程序能够处理来自任何将提供标准音频文件格式（MP3、AIFF、WAV等）的应用程序的音频。
据我所知，我所需要做的就是将CFBundleDocumentTypes密钥和相关的子数据添加到我的应用程序的Info.plist中
<key>CFBundleDocumentTypes</key>
<array>
<dict>
<key>CFBundleTypeIconFiles</key>
<array>
<string>scrubbulator-icon</string>
</array>
<key>CFBundleTypeName</key>
<string>Audio</string>
<key>LSHandlerRank</key>
<string>Alternative</string>
<key>LSItemContentTypes</key>
<array>
<string>public.mp3</string>
</array>
</dict>
</array>
添加此代码不会在应用程序的"打开"菜单中显示我的应用程序（我正在iPhone上测试，使用Dropbox中的MP3作为文件源。AudioMemos和Evernote应用程序都是为Dropbox中一个MP3文件显示的，所以我知道支持该格式）。是否有明显的我做错了什么，或者我还需要实施其他什么？
（注意：我没有在我的Info.plist中设置UTExportedTypeDeclarations项目，因为我知道这些项目仅对自定义UTI是必要的。由于我使用的是系统UTI，我认为它不应该是必要的，但如果我错了，请纠正我。）
编辑
我添加了以下导出的UTI类型，但没有成功：
<key>UTExportedTypeDeclarations</key>
<array>
<dict>
<key>UTTypeConformsTo</key>
<array>
<string>kUTTypeMP3</string>
</array>
<key>UTTypeDescription</key>
<string>Audio file</string>
<key>UTTypeIdentifier</key>
<string>kUTTypeMP3</string>
<key>UTTypeTagSpecification</key>
<dict>
<key>public.filename-extension</key>
<array>
<string>mp3</string>
</array>
</dict>
</dict>
</array>
对于所有标准文件格式：
<key>CFBundleDocumentTypes</key>
<array>
<dict>
<key>CFBundleTypeName</key>
<string>Unknown File</string>
<key>LSHandlerRank</key>
<string>Alternate</string>
<key>LSItemContentTypes</key>
<array>
<string>public.calendar-event</string>
<string>public.database</string>
<string>public.executable</string>
<string>public.data</string>
<string>public.content </string>
<string>public.item</string>
</array>
</dict>
<dict>
<key>CFBundleTypeName</key>
<string>Video</string>
<key>LSHandlerRank</key>
<string>Alternate</string>
<key>LSItemContentTypes</key>
<array>
<string>public.video</string>
</array>
</dict>
<dict>
<key>CFBundleTypeName</key>
<string>Image</string>
<key>LSHandlerRank</key>
<string>Alternate</string>
<key>LSItemContentTypes</key>
<array>
<string>public.image</string>
</array>
</dict>
<dict>
<key>CFBundleTypeName</key>
<string>Web Archive</string>
<key>LSHandlerRank</key>
<string>Alternate</string>
<key>LSItemContentTypes</key>
<array>
<string>com.apple.webarchive</string>
</array>
</dict>
<dict>
<key>CFBundleTypeName</key>
<string>iWork Keynote</string>
<key>LSHandlerRank</key>
<string>Alternate</string>
<key>LSItemContentTypes</key>
<array>
<string>com.apple.keynote.key</string>
<string>com.apple.iwork.keynote.key</string>
<string>com.apple.iwork.keynote.kth</string>
</array>
</dict>
<dict>
<key>CFBundleTypeName</key>
<string>iWork Numbers</string>
<key>LSHandlerRank</key>
<string>Alternate</string>
<key>LSItemContentTypes</key>
<array>
<string>com.apple.numbers.numbers</string>
<string>com.apple.iwork.numbers.numbers</string>
<string>com.apple.iwork.numbers.template</string>
</array>
</dict>
<dict>
<key>CFBundleTypeName</key>
<string>iWork Pages</string>
<key>LSHandlerRank</key>
<string>Alternate</string>
<key>LSItemContentTypes</key>
<array>
<string>com.apple.page.pages</string>
<string>com.apple.iwork.pages.pages</string>
<string>com.apple.iwork.pages.template</string>
</array>
</dict>
<dict>
<key>CFBundleTypeName</key>
<string>OpenDocument Spreadsheet</string>
<key>LSHandlerRank</key>
<string>Alternate</string>
<key>LSItemContentTypes</key>
<array>
<string>org.oasis.opendocument.spreadsheet</string>
</array>
</dict>
<dict>
<key>CFBundleTypeName</key>
<string>OpenDocument Presentation</string>
<key>LSHandlerRank</key>
<string>Alternate</string>
<key>LSItemContentTypes</key>
<array>
<string>org.oasis.opendocument.presentation</string>
</array>
</dict>
<dict>
<key>CFBundleTypeName</key>
<string>OpenDocument Text</string>
<key>LSHandlerRank</key>
<string>Alternate</string>
<key>LSItemContentTypes</key>
<array>
<string>org.oasis.opendocument.text</string>
</array>
</dict>
<dict>
<key>CFBundleTypeName</key>
<string>Folder</string>
<key>LSHandlerRank</key>
<string>Alternate</string>
<key>LSItemContentTypes</key>
<array>
<string>public.folder</string>
</array>
</dict>
<dict>
<key>CFBundleTypeName</key>
<string>Audio</string>
<key>LSHandlerRank</key>
<string>Alternate</string>
<key>LSItemContentTypes</key>
<array>
<string>public.audio</string>
<string>public.mp3</string>
<string>public.mpeg-4-audio</string>
<string>com.apple.protected-mpeg-4-audio</string>
<string>public.aifc-audio</string>
<string>com.apple.coreaudio-format</string>
<string>public.aiff-audio</string>
</array>
</dict>
<dict>
<key>CFBundleTypeName</key>
<string>Movie</string>
<key>LSHandlerRank</key>
<string>Alternate</string>
<key>LSItemContentTypes</key>
<array>
<string>public.movie</string>
<string>public.3gpp2</string>
<string>public.3gpp</string>
<string>public.mpeg</string>
<string>com.apple.quicktime-movie</string>
<string>public.mpeg-4</string>
</array>
</dict>
<dict>
<key>CFBundleTypeName</key>
<string>GIF image</string>
<key>LSHandlerRank</key>
<string>Alternate</string>
<key>LSItemContentTypes</key>
<array>
<string>com.compuserve.gif</string>
</array>
</dict>
<dict>
<key>CFBundleTypeName</key>
<string>PNG image</string>
<key>LSHandlerRank</key>
<string>Alternate</string>
<key>LSItemContentTypes</key>
<array>
<string>public.png</string>
</array>
</dict>
<dict>
<key>CFBundleTypeName</key>
<string>TIFF image</string>
<key>LSHandlerRank</key>
<string>Alternate</string>
<key>LSItemContentTypes</key>
<array>
<string>public.tiff</string>
</array>
</dict>
<dict>
<key>CFBundleTypeName</key>
<string>JPEG image</string>
<key>LSHandlerRank</key>
<string>Alternate</string>
<key>LSItemContentTypes</key>
<array>
<string>public.jpeg</string>
</array>
</dict>
<dict>
<key>CFBundleTypeName</key>
<string>XML</string>
<key>LSHandlerRank</key>
<string>Alternate</string>
<key>LSItemContentTypes</key>
<array>
<string>public.xml</string>
</array>
</dict>
<dict>
<key>CFBundleTypeName</key>
<string>HTML</string>
<key>LSHandlerRank</key>
<string>Alternate</string>
<key>LSItemContentTypes</key>
<array>
<string>public.html</string>
<string>public.xhtml</string>
</array>
</dict>
<dict>
<key>CFBundleTypeName</key>
<string>Rich Text</string>
<key>LSHandlerRank</key>
<string>Alternate</string>
<key>LSItemContentTypes</key>
<array>
<string>public.rtf</string>
<string>com.apple.rtfd</string>
<string>com.apple.flat-rtfd</string>
</array>
</dict>
<dict>
<key>CFBundleTypeName</key>
<string>Text</string>
<key>LSHandlerRank</key>
<string>Alternate</string>
<key>LSItemContentTypes</key>
<array>
<string>public.text</string>
<string>public.plain-text</string>
<string>public.utf8-plain-text</string>
<string>public.utf16-external-plain-text</string>
<string>public.utf16-plain-text</string>
<string>com.apple.traditional-mac-plain-text</string>
<string>public.source-code</string>
<string>public.c-source</string>
<string>public.objective-c-source</string>
<string>public.c-plus-plus-source</string>
<string>public.objective-c-plus-plus-source</string>
<string>public.c-header</string>
<string>public.c-plus-plus-header</string>
<string>com.sun.java-source</string>
<string>public.script</string>
<string>public.shell-script</string>
</array>
</dict>
<dict>
<key>CFBundleTypeExtensions</key>
<array>
<string>zip</string>
<string>zipx</string>
</array>
<key>CFBundleTypeName</key>
<string>Zip archive</string>
<key>LSHandlerRank</key>
<string>Alternate</string>
<key>LSItemContentTypes</key>
<array>
<string>public.zip-archive</string>
<string>public.archive</string>
<string>com.pkware.zip-archive</string>
<string>com.pkware.zipx-archive</string>
</array>
</dict>
<dict>
<key>CFBundleTypeExtensions</key>
<array>
<string>rar</string>
<string>RAR</string>
</array>
<key>CFBundleTypeName</key>
<string>Rar archive</string>
<key>LSHandlerRank</key>
<string>Alternate</string>
<key>LSItemContentTypes</key>
<array>
<string>com.rarlab.rar-archive</string>
<string>public.archive</string>
</array>
</dict>
<dict>
<key>CFBundleTypeExtensions</key>
<array>
<string>7z</string>
<string>7Z</string>
</array>
<key>CFBundleTypeName</key>
<string>7z archive</string>
<key>LSHandlerRank</key>
<string>Alternate</string>
<key>LSItemContentTypes</key>
<array>
<string>org.7-zip.7-zip-archive</string>
<string>public.archive</string>
</array>
</dict>
<dict>
<key>CFBundleTypeName</key>
<string>Waveform audio</string>
<key>LSHandlerRank</key>
<string>Alternate</string>
<key>LSItemContentTypes</key>
<array>
<string>com.microsoft.waveform-audio</string>
</array>
</dict>
<dict>
<key>CFBundleTypeName</key>
<string>Windows icon image</string>
<key>LSHandlerRank</key>
<string>Alternate</string>
<key>LSItemContentTypes</key>
<array>
<string>com.microsoft.ico</string>
<string>com.apple.icns</string>
</array>
</dict>
<dict>
<key>CFBundleTypeName</key>
<string>Windows bitmap image</string>
<key>LSHandlerRank</key>
<string>Alternate</string>
<key>LSItemContentTypes</key>
<array>
<string>com.microsoft.bmp</string>
</array>
</dict>
<dict>
<key>CFBundleTypeName</key>
<string>Microsoft PowerPoint</string>
<key>LSHandlerRank</key>
<string>Alternate</string>
<key>LSItemContentTypes</key>
<array>
<string>com.microsoft.powerpoint.ppt</string>
<string>org.openxmlformats.presentationml.presentation</string>
</array>
</dict>
<dict>
<key>CFBundleTypeName</key>
<string>Microsoft Excel</string>
<key>LSHandlerRank</key>
<string>Alternate</string>
<key>LSItemContentTypes</key>
<array>
<string>org.openxmlformats.spreadsheetml.sheet</string>
<string>com.microsoft.excel.xls</string>
</array>
</dict>
<dict>
<key>CFBundleTypeName</key>
<string>Microsoft Word</string>
<key>LSHandlerRank</key>
<string>Alternate</string>
<key>LSItemContentTypes</key>
<array>
<string>com.microsoft.word.doc</string>
<string>com.microsoft.word.wordml</string>
<string>org.openxmlformats.wordprocessingml.document</string>
</array>
</dict>
<dict>
<key>CFBundleTypeName</key>
<string>PDF</string>
<key>LSHandlerRank</key>
<string>Alternate</string>
<key>LSItemContentTypes</key>
<array>
<string>com.adobe.pdf</string>
</array>
</dict>
</array>
您应该使用Alternate而不是Alternative
<key>LSHandlerRank</key>
<string>Alternate</string>
<key>CFBundleDocumentTypes</key>
<array>
<dict>
<key>CFBundleTypeExtensions</key>
<array>
<string>"*"</string>
</array>
<key>CFBundleTypeName</key>
<string>Unknown</string>
<key>LSItemContentTypes</key>
<array>
<string>public.data</string>
</array>
</dict>
</array>