为什么MPMovieLoadState的状态为5？

Question

我发现MPMoviePlayerController.h，有

enum { 
    MPMovieLoadStateUnknown  = 0, 
    MPMovieLoadStatePlayable  = 1 << 0, 
    MPMovieLoadStatePlaythroughOK = 1 << 1, // Playback will be automatically started in this state when shouldAutoplay is YES 
    MPMovieLoadStateStalled  = 1 << 2, // Playback will be automatically paused in this state, if started 
}; 
typedef NSInteger MPMovieLoadState; 

，但是当我做了

NSLog(@"%d",player.loadState)

它打印出5或有时3，它是如何发生的呢？据我所知在LoadState具有价值0,1,2,4是指开发者文档。 谢谢！

Answer 1

playState是一个位掩码。位的任何数字都可以设置，如

MPMovieLoadStatePlaythroughOK | MPMovieLoadStatePlayable 

检查状态是这样的：

MPMovieLoadState state = [playerController loadState]; 
if(state & MPMovieLoadStatePlaythroughOK) { 
     NSLog(@"State is Playthrough OK"); 
}