objective c - Creating an application that can open files of a given format -

I have an app that has been written in Obj-C. Info.plist has a list of file types, which can open the app. I'm pretty sure that this is working because when I try to drag an unacceptable type of file, the app is not highlighted, but when I drag a file of an acceptable type, it highlights it and Leaves me / P>

When I leave, the app starts, right, still, I get a dialog:

The document "foo.tiff" could not be opened. DocView can not open the file in "TIFF file" format.

I have this in my info.plist

  & lt; Key & gt; CF Band Type Extension & lt; / Key & gt; & Lt; Array & gt; & Lt; String & gt; TIF & lt; / String & gt; & Lt; String & gt; Tiff & lt; / String & gt; & Lt; / Array & gt; & Lt; Key & gt; CFBundleTypeIconFile & lt; / Key & gt; & Lt; String & gt; TIFFFile.icns & lt; / String & gt; & Lt; Key & gt; CFBundleTypeName & lt; / Key & gt; & Lt; String & gt; TIFF file & lt; / String & gt; & Lt; Key & gt; CFBundleTypeOSTypes & lt; / Key & gt; & Lt; Array & gt; & Lt; String & gt; TIFF & lt; / String & gt; & Lt; / Array & gt; & Lt; Key & gt; CFBundleTypeRole & lt; / Key & gt; & Lt; String & gt; Viewer & lt; / String & gt; & Lt; Key & gt; LSHandlerRank & lt; / Key & gt; & Lt; String & gt; Document / & lt; / String & gt;  

Thanks.

Does your app actually handle opening files?

If this is a NSDcast application, then you have to implement file reading methods like readFromData: ofType: error: . In a simple NSAPPin, your app representative should handle it in applications: OpenFile: . In both cases, you need to return yes to accept that you have successfully opened the file.

If you have implemented this, what message are you sending?