ios - 无法在另一个 View Controller 中显示缩略图

Question

- (void)displayThumbnail
{
    AVURLAsset *asset = [[AVURLAsset alloc] initWithURL:[self outputURL] options:nil];
    AVAssetImageGenerator *gen = [[AVAssetImageGenerator alloc] initWithAsset:asset];
    gen.appliesPreferredTrackTransform = YES;
    CMTime time = CMTimeMakeWithSeconds(1, 30);
    NSError *error = nil;
    CMTime actualTime;
    CGImageRef imageref = [gen copyCGImageAtTime:time actualTime:&actualTime error:&error];
    UIImage *thumbnail = [[UIImage alloc] initWithCGImage:imageref];
    CGImageRelease(imageref);

    UIStoryboard *mainStoryboard = [UIStoryboard storyboardWithName:@"MainStoryboard" bundle:nil];

    MainViewController *controller = [mainStoryboard instantiateViewControllerWithIdentifier:@"MainViewController"];

    controller.imageView.image = thumbnail;
}

我试图在另一个 View Controller 中显示录制视频的缩略图，但没有显示任何内容。我错过了什么吗？

Answer 1

在MainViewController.h中获取UIImage类型的属性

@property(strong,nonatomic) UIImage* thumbnailImg;

在 MainViewController.m 中

self.imageView.image = self.thumbnailImg;

设置这个属性

[controller setThumbnailImg: thumbnail]