问替代用于iPhone应用程序或Mobile的动画PNG文件，目标是模拟短视频剪辑的即时播放。

EN

<div class="thumb" style="background-image: url(vid1.png); width:200px; height:100px" data-frames="30">
</div>

$('.thumb').bind('click', function() {
    var $img = $(this);
    var startTime = Date.now();
    var frames = $img.attr('data-frames');
    var width = $img.width();

    setInterval(function() {
    var frame = Math.round((Date.now() - startTime) / 100) % frames;
        $img.css('background-position', -frame * width + 'px 0';
    }, 100);
});

- (void)readySet {

    NSMutableArray *images = [NSMutableArray array];

    for (int i=0; i<kIMAGE_COUNT; i++) {
        NSString *fn = [NSString stringWithFormat:@"image%d.png"];
        UIImage *image = [UIImage imageNamed:fn];
        [images addObject:image];
    }
    self.myUIImageView.animationImages = [NSArray arrayWithArray:images];
}

// go runs fast if we run readySet first
//
- (void)go {

    [self.myUIImageView startAnimating];
}

// A little more complex because we need to get notified that it's ready to play,
// but the same principal...

- (void)readySet {

    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(moviePlayerLoadStateChanged:) name:MPMoviePlayerLoadStateDidChangeNotification object:nil];

    MPMoviePlayerController *player = [[MPMoviePlayerController alloc] initWithContentURL:url];

    player.shouldAutoplay = NO;
    [player prepareToPlay];
    self.mp = player;
}

- (void)moviePlayerLoadStateChanged:(NSNotification*)notification {

    MPMovieLoadState state = [self.mp loadState];
    if (state & MPMovieLoadStatePlaythroughOK) {
        [[NSNotificationCenter defaultCenter] removeObserver:self name:MPMoviePlayerLoadStateDidChangeNotification object:nil];

        self.mp.view.frame = CGRect(/* where it will appear */)
    }
}

// go runs fast if we run readySet first (and the movie is ready)
//
- (void)go {

    MPMovieLoadState state = [self.mp loadState];
    if (state & MPMovieLoadStatePlaythroughOK) {
        [self.view addSubview:self.mp.view];
        [self.mp play];
    } else {
        self.mp.shouldAutoplay = YES;
    }
}