AVAudioPlayer isPlaying始终返回null [英] AVAudioPlayer isPlaying always return null

问题描述

我在AVAudioPlayer类中遇到了一个奇怪的问题. 每次我尝试访问其中一个属性时，它们都为空.

I'm experiencing an odd problem with AVAudioPlayer class. Everytime I try to access one of it's properties they are null.

// Get the file path to the song to play.
 NSString *filePath = [[[NSBundle mainBundle] pathForResource:pSound.fileName 
               ofType:pSound.fileType] retain];

 // Convert the file path to a URL.
 NSURL *fileURL = [[NSURL alloc] initFileURLWithPath:filePath];

 NSError* err;
 //Initialize the AVAudioPlayer
 self.audioPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL:fileURL error:&err];

    if( err ){
  NSLog(@"Initializing failed with reason: %@", [err localizedDescription]);
 }
 else{
  [self.audioPlayer setDelegate:self];
  [self.audioPlayer prepareToPlay];
  self.playCount = self.playCount + 1;
        NSLog(@"%@", [self.audioPlayer isPlaying]); //this displays null; also if I call it at a later time
 };

 [filePath release];
 [fileURL release];

有什么想法吗?

奇怪的是，当我保存isPlay到bool并打印bool时，我得到了一个值...

Oddly enough when I save isPlaying to a bool and print the bool I get a value...

推荐答案

NSLog(@"%@", [self.audioPlayer isPlaying]); 

％@-表示您要打印[yourObject toString]的结果 因此，如果您要检查[self.audioPlayer isPlaying]返回的布尔值-您应该使用％d.

%@ - mean that you want to print result of [yourObject toString] so if you want to check bool value returned by [self.audioPlayer isPlaying] - you should use %d.

p.s.请勿致电[audioPlayer播放]； ;)

p.s. don't foget call [audioPlayer play]; ;)

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