iPhone universal app. MoviePlayer.framwork problem.

Question

I have application based on 3.0 iPhone OS SDK One of tasks is playing video (I use MPMoviePlayerController for this task) Now I try to make universal app working on both 3.0 and 3.2 OS I did all steps described in apple documentation: Upgrade Current Target for iPad; make run-time checking for symbols using

[[UIDevice currentDevice] respondsToSelector:@selector(userInterfaceIdiom)]

function. But when I start my application on device - iPhone with OS 3.1.3 my apllication is crashes with next log:

Tue May 25 18:00:28 unknown SpringBoard[24] <Notice>: MultitouchHID(208b30) uilock state: 1 -> 0
Tue May 25 18:00:29 unknown SpringBoard[24] <Notice>: MultitouchHID(292580) device bootloaded
Tue May 25 18:00:34 unknown UIKitApplication:...[0xaa0f][1517] <Notice>: dyld: Symbol not found: _MPMoviePlayerWillEnterFullscreenNotification
Tue May 25 18:00:34 unknown UIKitApplication:...[0xaa0f][1517] <Notice>:   Referenced from: /var/mobile/Applications/876EA35E-5756-436B-A9E2-5481D4D62050/....app/...
Tue May 25 18:00:34 unknown UIKitApplication:...[0xaa0f][1517] <Notice>:   Expected in: /System/Library/Frameworks/MediaPlayer.framework/MediaPlayer
Tue May 25 18:00:35 unknown kernel[0] <Debug>: launchd[1517] Builtin profile: container (seatbelt)
Tue May 25 18:00:35 unknown kernel[0] <Debug>: launchd[1517] Container: /private/var/mobile/Applications/876EA35E-5756-436B-A9E2-5481D4D62050 (seatbelt)
Tue May 25 18:00:35 unknown ReportCrash[1518] <Notice>: Formulating crash report for process cnetmobile[1517]
Tue May 25 18:00:36 unknown com.apple.launchd[1] <Warning>: (UIKitApplication:...[0xaa0f]) Job appears to have crashed: Trace/BPT trap
Tue May 25 18:00:36 unknown com.apple.launchd[1] <Warning>: (UIKitApplication:...[0xaa0f]) Throttling respawn: Will start in 2147483646 seconds
Tue May 25 18:00:36 unknown SpringBoard[24] <Warning>: Application '...' exited abnormally with signal 5: Trace/BPT trap
Tue May 25 18:00:36 unknown ReportCrash[1518] <Error>: Saved crashreport to /var/mobile/Library/Logs/CrashReporter/..._2010-05-25-180034_...-iPhone.plist using uid: 0 gid: 0, synthetic_euid: 501 egid: 0
Tue May 25 18:01:36 unknown SpringBoard[24] <Notice>: MultitouchHID(208b30) uilock state: 0 -> 1

As you can see the error is "Symbol not found: _MPMoviePlayerWillEnterFullscreenNotification". This symbol is notification available in MediaPlayer.framework starting from iPhone OS 3.2

So, what am I doing wrong? What I should do to have universal application working correct on OS 3.2 (with new available functionality) and older OSes (with their functionality)?

Answer 1

The content of that constant is the string @"MPMoviePlayerWillEnterFullscreenNotification", so you can use this string in place of the constant.

Alternatively, you could

1. use functions like dlsym to get the symbol at runtime; or
2. make that symbol weakly linked (= doing step 1 automatically)