ios - 如何为 AVAudioEngine 设置完成处理程序

Question

我正在使用这个方法来播放音频文件；

-(void)playOnMainThread:(id)参数

{
   [self playAudio];

    AVAudioEngine *engine = [[AVAudioEngine alloc] init];
    AVAudioPlayerNode *node = [[AVAudioPlayerNode alloc] init];
    [engine attachNode:node];
    AVAudioUnitTimePitch *pitch = [[AVAudioUnitTimePitch alloc] init];
    pitch.pitch = 100;
    pitch.rate = 2;
    [engine attachNode:pitch];
    AVAudioMixerNode *mixerNode = engine.mainMixerNode;
    [engine connect:node to:pitch format:[mixerNode outputFormatForBus:0]];
    [engine connect:pitch to:mixerNode format:[mixerNode outputFormatForBus:0]];

    AVAudioFile *audioFile = [[AVAudioFile alloc] initForReading:recorder.url error:&error];
    if (error)
        NSLog(@"AVAudioPlayer error %@, %@", error, [error userInfo]);
    if (audioFile != nil) {
        [node scheduleFile:audioFile atTime:nil completionHandler:nil];
        [engine startAndReturnError:nil];
        [node play];
    }    
}

但是我需要设置一个completionhandler，这是我试过的；

-(void)stopTalking:(AVAudioNodeCompletionHandler)handler
//-(void)stopTalking
{

    isPlaying = NO;
    [self unschedule:@selector(RepeatSpeackAction)];

    [self schedule:@selector(StartGAmeCall)];

    [stand setDisplayFrame:[[CCSpriteFrameCache sharedSpriteFrameCache] spriteFrameByName:@"Turn1.png"]];

    if(video==true) {
        cases=1;
        [self addaudiotoDict];
    }

}

我试图通过这样使用它来调用它；

[node scheduleFile:audioFile atTime:nil completionHandler:stopTalking];

如果没有成功，我该如何调用完成处理程序？

Answer 1

您需要使用 GCD block ，而不是方法，作为 completionHandler 参数:

[node scheduleFile:audioFile atTime:nil completionHandler:^{

    // Your "stopTalking" code goes here...

}];