Hi all, Wanted to try and help some people out here. It took a while to figure this out, so hope it helps ;).
So, if you are calling ContentResolver.query() and getting back a null Cursor, then you might want to ensure that you are actually passing in a valid URI. Only URI's with the content:// scheme can be queried, while URI's with the file:// scheme cannot (and will just return null)! To test this, call getScheme() on your URI, and compare it to the SCHEME_* constants in the ContentResolver class. It seems that almost anything coming from the SD card has a file:// prefix aka SCHEME_FILE. In my case, this was large images. Also, (and this is just total speculation) sometimes I magically get a SCHEME_CONTENT prefix, which I would attribute to caching of the image. This was unpredictable, but I ended up having to plan for both FILE and CONTENT to get the problem fixed 100%. This is not a bug, it is documented, although it could use a bit more attention in the docs - It would be nice if the format used in ( http://developer.android.com/reference/android/content/ContentResolver.html#openOutputStream%28android.net.Uri,%20java.lang.String%29 ) was also used in ( http://developer.android.com/reference/android/content/ContentResolver.html#query%28android.net.Uri,%20java.lang.String[],%20java.lang.String,%20java.lang.String[],%20java.lang.String%29 ). This is definitely intended behavior though, see ( http://android.git.kernel.org/?p=platform/frameworks/base.git;a=blob;f=core/java/android/content/ContentResolver.java;h=74144fc5608fa5b3c219f887f539f8ff12a1efe6;hb=HEAD#l145 ) and ( http://android.git.kernel.org/?p=platform/frameworks/base.git;a=blob;f=core/java/android/content/ContentResolver.java;h=74144fc5608fa5b3c219f887f539f8ff12a1efe6;hb=HEAD#l572 ) Thanks, Hamilton PS - someone please let me know how to add links to my post! --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/android-developers?hl=en -~----------~----~----~----~------~----~------~--~---
