如何将KVO添加到MPMoviePlayer currentPlaybackTime? [英] How to add a KVO to MPMoviePlayer currentPlaybackTime?

问题描述

如何将KVO添加到MPMoviePlayer类的currentPlaybackTime属性中?

How can I add a KVO to the currentPlaybackTime property of a MPMoviePlayer class?

推荐答案

您不能将KVO添加到currentPlaybackTime中，因为该属性未明确声明为与KVO兼容.

You cannot add a KVO to currentPlaybackTime since the property is not explicitly declared as KVO compatible.

相反，您可以尝试使用以下代码定期轮询玩家并存储位置:

Instead, you could try polling the player regularly and storing the position, with code such as:

- (void) BeginPlayerPolling {
self.pollPlayerTimer = [NSTimer scheduledTimerWithTimeInterval:5
                                                       target:self 
                                                     selector:@selector(PollPlayerTimer_tick:)
                                                     userInfo:nil 
                                                      repeats:YES];  

}

- (void) PollPlayerTimer_tick:(NSObject *)sender {
// Store current playback position
if (player.playbackState == MPMoviePlaybackStatePlaying)
    lastRecordedPlaybackTime = player.currentPlaybackTime;
}

- (void) EndPlayerPolling {
if (pollPlayerTimer != nil)
{
    [pollPlayerTimer invalidate];
    self.pollPlayerTimer = nil;
}
}

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