在iOS中注册png文件类型

Question

I am trying to register png files in order to open them from within the Mail app on the iPhone, but I never get an "Open In..." menu from within the Mail app. When I am using the same plist for pdf type (com.adobe.pdf), it works perfectly.

Does anyone know if there is any limitation when registering png files?

Here is CFBundleDocumentTypes in my plist file:

<key>CFBundleDocumentTypes</key>
<array>
    <dict>
        <key>CFBundleTypeName</key>
        <string>kUTTypePNG</string>
        <key>LSHandlerRank</key>
        <string>Alternate</string>
        <key>LSItemContentTypes</key>
        <array>
            <string>public.png</string>
        </array>
    </dict>
</array>

Answer 1

I was looking for an answer for the same question but for doc extension. Anyway here is a list of the 3rd party extensions provided by Apple.

https://developer.apple.com/library/mac/#documentation/Miscellaneous/Reference/UTIRef/Articles/System-DeclaredUniformTypeIdentifiers.html