Question

我可以使用MPMoviePlayerController播放视频。方法requestThumbnailImagesAtTimes允许我多次放入一个数组来获取缩略图，但在MPMoviePlayerThumbnailImageRequestDidFinishNotification我只能在我的时间数组中第一次返回一个图像。如何在我的阵列中获取其他时间请求的其他图像？

在我的viewDidLoad：

中

[self.movieController requestThumbnailImagesAtTimes:self.timesArray timeOption:MPMovieTimeOptionExact];
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(MPMoviePlayerThumbnailImageRequestDidFinishNotification:) name:MPMoviePlayerThumbnailImageRequestDidFinishNotification object:self.movieController];

通知：

-(void)MPMoviePlayerThumbnailImageRequestDidFinishNotification: (NSNotification*)note
{

NSDictionary * userInfo = [note userInfo];
UIImage *image = (UIImage *)[userInfo objectForKey:MPMoviePlayerThumbnailImageKey];
if(image!=NULL)
    [self.trippingBalls setImage:image];

}

Answer 1

可能会帮助你...

-(UIImage *)generateThumbImage : (NSString *)filepath
{
    NSURL *url = [NSURL fileURLWithPath:filepath];

    AVAsset *asset = [AVAsset assetWithURL:url];
    AVAssetImageGenerator *imageGenerator = [[AVAssetImageGenerator alloc]initWithAsset:asset];
    CMTime time = [asset duration];
    time.value = 0;
    CGImageRef imageRef = [imageGenerator copyCGImageAtTime:time actualTime:NULL error:NULL];
    UIImage *thumbnail = [UIImage imageWithCGImage:imageRef];
    CGImageRelease(imageRef);  // CGImageRef won't be released by ARC

    return thumbnail;
}

time.value = 1000 //以毫秒为单位的时间

Answer 2

我最后通过将我收到的每个UIImage添加到一个数组中来解决这个问题。

我在我的MPMoviePlayerController上添加了一个UIGestureRecognizer，所以在每个tap方法中，我将从Notification收到的UIImage添加到我的数组中。

点击方法：

- (void)handleRollTap:(UITapGestureRecognizer *)sender
{
float time = [self.movieController currentPlaybackTime];
[self.timesMutableArray addObject:[NSNumber numberWithFloat:time]];
self.view.backgroundColor = [UIColor blueColor];

self.timesArrayToPass = [NSArray arrayWithArray:self.timesMutableArray];
[self.movieController requestThumbnailImagesAtTimes:self.timesArrayToPass timeOption:MPMovieTimeOptionExact];
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(MPMoviePlayerThumbnailImageRequestDidFinishNotification:) name:MPMoviePlayerThumbnailImageRequestDidFinishNotification object:self.movieController];

[self.images addObject:self.image];

NSLog(@"%@", self.images);
}

通知：

-(void)MPMoviePlayerThumbnailImageRequestDidFinishNotification: (NSNotification*)note
{
   NSDictionary * userInfo = [note userInfo];
self.image = (UIImage *)[userInfo objectForKey:MPMoviePlayerThumbnailImageKey];
    [self.imageView setImage:self.image];
}

如何使用requestThumbnailImagesAtTimes返回多个缩略图图像

2 个答案: