requestAVAssetForVideo 不显示完成块

【问题标题】：requestAVAssetForVideo doesn't show completion blockrequestAVAssetForVideo 不显示完成块
【发布时间】：2017-01-17 19:10:09
【问题描述】：

我有这个代码来加载 PHAsset：

PHVideoRequestOptions *options = [[PHVideoRequestOptions alloc] init];
options.networkAccessAllowed = YES;

[[PHImageManager defaultManager] requestAVAssetForVideo:[videos objectAtIndex:index]  options:options resultHandler:^(AVAsset *asset, AVAudioMix *audioMix, NSDictionary *info) {
    selectedAsset = asset;
}];

它非常适合存储在设备上的视频。但如果代码应该从 iCloud 加载视频，它不会调用完成块。你能帮帮我吗？

【问题讨论】：

标签： objective-c xcode avfoundation icloud photosframework

【解决方案1】：

请尝试其他代码 1 到 3

PHVideoRequestOptions *options = [[PHVideoRequestOptions alloc] init];
options.networkAccessAllowed = YES;

//Additional code 1
dispatch_semaphore_t semaphore = dispatch_semaphore_create(1);

[[PHImageManager defaultManager] requestAVAssetForVideo:[videos objectAtIndex:index]  options:options resultHandler:^(AVAsset *asset, AVAudioMix *audioMix, NSDictionary *info) {
    selectedAsset = asset;

//Additional code 2
dispatch_semaphore_signal(semaphore);

}];

//Additional code 3
dispatch_semaphore_wait(semaphore, DISPATCH_TIME_FOREVER);

【讨论】：