Objective c 电影回放完成和过渡'；s效应

我想知道如何添加过渡（视频开始时淡入，视频结束时淡出）

你能帮他完成这项任务吗？我有点迷茫于过渡期，以前从未玩过

这是我的密码

- (void) startSlideShow
{
    NSURL *url = [NSURL fileURLWithPath:[[NSBundle mainBundle] 
                                         pathForResource:@"2" ofType:@"mov"]];


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

    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(moviePlayBackDidFinish:)
                                                 name:MPMoviePlayerPlaybackDidFinishNotification
                                               object:moviePlayer];
    moviePlayer.view.frame = CGRectMake(0, 0, 768, 1024);

    moviePlayer.controlStyle = MPMovieControlStyleDefault;
    moviePlayer.shouldAutoplay = YES;
    [self.view addSubview:moviePlayer.view];
    [moviePlayer setFullscreen:YES animated:YES];
   }


-(void)moviePlayBackDidFinish: (NSNotification*)notification
{ 
    MPMoviePlayerController *moviePlayer = [notification object];

    [[NSNotificationCenter defaultCenter] removeObserver:self      
                                                    name:MPMoviePlayerPlaybackDidFinishNotification
                                                  object:moviePlayer];

    if ([moviePlayer respondsToSelector:@selector(setFullscreen:animated:)])
    {
        // the transition should be around here... (fade out)
        [moviePlayer.view removeFromSuperview];
    }
    [moviePlayer release];

    [self checkResources];
}

---

您可以在播放电影之前捕获UI的屏幕截图

UIGraphicsBeginImageContext(view.frame.size);
[view.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *screenshotOfView = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();

然后添加电影播放器，然后将图像添加为UIImageView（例如[[UIApplication sharedApplication]keyWindow]）。然后将图像淡出

（我不知道您是否也可以从0-1为moviePlayer.view.alpha设置动画）

---

通过设置alpha值的动画，可以实现基本的淡入淡出/淡出：

view.alpha = 0.0;
[UIView animateWithDuration: 0.35 animations:^{
    view.alpha = 1.0;
}];

---

我不明白。。。我想要的是在视频/图像开始时应用淡入/淡出效果。谢谢你帮我，伙计！通过设置alpha值的动画，可以实现基本的淡入淡出/淡出。我将编辑我的答案。