相关疑难解决方法(0)

我有一个viewController包含以下方法:

- (IBAction) playMovie {
    NSURL *url = [NSURL fileURLWithPath:[[NSBundle mainBundle] pathForResource:@"test" ofType:@"m4v"]];

    MPMoviePlayerController *moviePlayer = [[MPMoviePlayerController alloc] initWithContentURL:url];
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(moviePlayBackDidFinish:)
                                       name:MPMoviePlayerPlaybackDidFinishNotification
                                       object:moviePlayer];

    moviePlayer.controlStyle = MPMovieControlStyleNone;
    moviePlayer.shouldAutoplay = YES;

    [self.view addSubview:moviePlayer.view];
    [moviePlayer setFullscreen:YES animated:YES];
}

由于错误,我无法编译代码:

未定义的符号:

  "_MPMoviePlayerPlaybackDidFinishNotification", referenced from:
      _MPMoviePlayerPlaybackDidFinishNotification$non_lazy_ptr in AnotherViewController.o
     (maybe you meant: _MPMoviePlayerPlaybackDidFinishNotification$non_lazy_ptr)
  "_OBJC_CLASS_$_MPMoviePlayerController", referenced from:
      objc-class-ref-to-MPMoviePlayerController in AnotherViewController.o
ld: symbol(s) not found
collect2: ld returned 1 exit status

这条消息对我没有意义.

我打算将此方法用作视图控制器的一部分.我是否必须为播放器创建单独的视图控制器,或者情况并非如此？

我在创建这个项目时使用了SDK 3.1.2,但是根据新的API规则完全重写了playMovie方法.当前的SDK版本是4.0.1