創建AVPlayerLayer會導致模擬器崩潰

Question

我有一個類在回調中返回AVPlayer和AVSynchronisedLayer。 當我使用AVPlayer初始化AVPlayerLayer時，我遇到了崩潰（僅在模擬器中發生）。 代碼如下所示：

  self.projectPlayer = [[MYMobilePlayer alloc] init];
  [self.projectPlayer setDelegate:self]; 
  [self.projectPlayer returnPlayerForProjectScene:self.projectScene andCallback:^(NSError *error, AVPlayer *player, AVSynchronizedLayer *syncLayer) {


      self.syncLayer = syncLayer;
      AVPlayerLayer *playerLayer = [AVPlayerLayer playerLayerWithPlayer:player];
      NSLog(@"%@",playerLayer); // Also crashes if I assign to private member variable
      // More code that uses the playerLayer - not needed to illustrate the problem

  }];

回調中返回的對象是正確的，所以我認為我不需要顯示創建並返回它們的代碼。

堆棧跟蹤如下所示（不是很有幫助）。

知道這里可能會發生什么嗎？

Answer 1

應始終在主線程上調用UIKit代碼。 您的returnPlayerForProjectScene回調發生在其他一些視頻處理線程上。 將有問題的代碼分派到主隊列應該可以修復崩潰：

[self.projectPlayer returnPlayerForProjectScene:self.projectScene andCallback:^(NSError *error, AVPlayer *player, AVSynchronizedLayer *syncLayer) {

    dispatch_async(dispatch_get_main_queue(), ^{

        self.syncLayer = syncLayer;
        AVPlayerLayer *playerLayer = [AVPlayerLayer playerLayerWithPlayer:player];
        NSLog(@"%@",playerLayer); // Also crashes if I assign to private member variable
        // More code that uses the playerLayer - not needed to illustrate the problem

    });
}];