Macos 如何检测电影停止播放？

我做了以下几件事——曾经演过一部电影（关于山狮），希望在电影结束时得到通知。但是通知从来没有接到过！谁能告诉我我做错了什么

- (void)playMovie:(QTMovie *)movie {
    [self.movieView.movie stop];

    if (movie) {
        self.movieView.movie = movie;
        [movie gotoBeginning];
        [movie play];

        [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(stopMovie:) name:QTMovieDidEndNotification object:self];
    }
}


- (void)stopMovie:(NSNotification *)notification {
    NSLog(@"stop movie!");
    [[NSNotificationCenter defaultCenter] removeObserver:self name:QTMovieDidEndNotification object:nil];
}

---

尝试更改为以下内容（请注意对象参数）：

[[NSNotificationCenter defaultCenter] addObserver:self
    selector:@selector(stopMovie:)
    name:QTMovieDidEndNotification
    object:movie];