在MPMoviePlayerController上调用renderInContext

Question

我正在尝试以编程方式从MPMoviePlayerController视频的当前帧中创建图像。我正在使用renderInContext调用播放器的view.layer然而创建的图像全部是黑色的视频播放器控件，但我希望看到视频的当前帧

我的代码（http://pastie.org/1020066）

UIGraphicsBeginImageContext(moviePlayer.view.bounds.size);
[moviePlayer.view.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *viewImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();

// I also tried this code (same results)

// moviePlayer is a subview of videoView (UIView object)
UIGraphicsBeginImageContext(videoView.bounds.size);
[videoView.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *viewImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();

Answer 1

如果您想获取电影的缩略图，则应该检查MPMoviePlayerController的thumbnailImageAtTime:timeOption:方法。