moviePlayBackDidFinish和Transition的效果 [英] moviePlayBackDidFinish and Transition's effect

问题描述

我想知道如何添加过渡(在视频开始播放时淡入，在视频结束播放时淡出).

i would like to know how to add a transition ( fade in when the video is getting to start and fade out when the video is finished ).

您能帮他完成这个任务吗，我有点迷失了过渡，从来没有在/之前玩过它:

Could you please help him in this task, i'm kind of lost with transition, never play with it before /:

这是我的代码

- (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];
}

推荐答案

您可以在播放电影之前捕获UI的屏幕截图.

You could capture a screenshot of your UI right before playing the movie.

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

然后添加MoviePlayer，然后在该图像的顶部添加图像作为UIImageView(例如[[UIApplication sharedApplication] keyWindow]).然后您将图像淡出.

Then you add your MoviePlayer and then you add the Image as UIImageView on top of that (eg [[UIApplication sharedApplication] keyWindow]). Then you fade the image out.

(我不知道您是否也可以从0-1开始对moviePlayer.view.alpha进行动画处理.)

(I don't know if you also could just animate the moviePlayer.view.alpha from 0-1).

可以通过设置Alpha值的动画来实现基本的淡入/淡出:

A basic fadein/fadeout can be achieved by animating the alpha value:

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

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