Objective c - ios：如何从相机胶卷中挑选视频

如何从相机胶卷中挑选视频

xml
NSPhotoLibraryUsageDescription
我们需要访问您的相册来选择视频

objective-c
#import 
PHAuthorizationStatus status = [PHPhotoLibrary authorizationStatus];
if (status == PHAuthorizationStatusAuthorized) {
    // 用户已授权访问相册，可以进行下一步操作
} else if (status == PHAuthorizationStatusDenied || status == PHAuthorizationStatusRestricted) {
    // 用户拒绝或无法访问相册，可以提示用户授权
} else if (status == PHAuthorizationStatusNotDetermined) {
    // 用户还未决定是否授权访问相册，可以请求授权
    [PHPhotoLibrary requestAuthorization:^(PHAuthorizationStatus status) {
        if (status == PHAuthorizationStatusAuthorized) {
            // 用户授权访问相册，可以进行下一步操作
        } else {
            // 用户拒绝授权访问相册，可以提示用户授权
        }
    }];
}

objective-c
PHFetchResult *videoFetchResult = [PHAsset fetchAssetsWithMediaType:PHAssetMediaTypeVideo options:nil];
NSMutableArray *videos = [NSMutableArray array];
[videoFetchResult enumerateObjectsUsingBlock:^(PHAsset *asset, NSUInteger idx, BOOL *stop) {
    [videos addObject:asset];
}];

objective-c
// 创建UICollectionView
UICollectionViewFlowLayout *layout = [[UICollectionViewFlowLayout alloc] init];
UICollectionView *collectionView = [[UICollectionView alloc] initWithFrame:self.view.bounds collectionViewLayout:layout];
[collectionView registerClass:[VideoCell class] forCellWithReuseIdentifier:@"VideoCell"];
collectionView.delegate = self;
collectionView.dataSource = self;
[self.view addSubview:collectionView];
// 实现UICollectionViewDelegate和UICollectionViewDataSource的相关方法
- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section {
    return videos.count;
}
- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath {
    VideoCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:@"VideoCell" forIndexPath:indexPath];
    PHAsset *asset = videos[indexPath.row];
    // 根据PHAsset获取视频的缩略图并设置给cell
    return cell;
}
- (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath {
    PHAsset *selectedAsset = videos[indexPath.row];
    // 用户选择了某个视频，可以进行相关操作，比如播放或上传
}