AVAudioPlayer问题

Question

使用AVAudio播放器播放超过1首歌曲

当第一首歌完成时，调用- (void)audioPlayerDidFinishPlaying:successfully:。

如果我使用该代码，它将正常工作

- (void)audioPlayerDidFinishPlaying:(AVAudioPlayer *)player successfully:(BOOL)flag
{
    NSString *tempString = @"/";
    tempString  = [tempString stringByAppendingString:name];
    NSString *path = [NSString stringWithFormat:@"%@",[[NSBundle mainBundle] resourcePath]];
    path = [path stringByAppendingString:tempString];
    NSURL *url = [NSURL fileURLWithPath:path];
    NSError *error;

    AVAudioPlayer  *audioPlayer101 = [[AVAudioPlayer alloc] initWithContentsOfURL:url    error:&error];

    [AppDelegate getAppdelegate].audioPlayerForPlay = audioPlayer101;
    [[AppDelegate getAppdelegate].audioPlayerForPlay play];
} 

它起作用了

但是，如果我不把实例放在音频播放器的预定义属性中，它就不能播放。

以下是代码

- (void)audioPlayerDidFinishPlaying:(AVAudioPlayer *)player successfully:(BOOL)flag
{
    NSString *tempString = @"/";
    tempString  = [tempString stringByAppendingString:name];
    NSString *path = [NSString stringWithFormat:@"%@",[[NSBundle mainBundle] resourcePath]];
    path = [path stringByAppendingString:tempString];
    NSURL *url = [NSURL fileURLWithPath:path];
    NSError *error;

    AVAudioPlayer  *audioPlayer101 = [[AVAudioPlayer alloc] initWithContentsOfURL:url    error:&error];
    [audioPlayer101  play];
} 

Answer 1

ARC代码

AVAudioPlayer  *audioPlayer101 = [[AVAudioPlayer alloc] initWithContentsOfURL:url    error:&error];
[audioPlayer101  play];

将针对非ARC编译为

AVAudioPlayer  *audioPlayer101 = [[AVAudioPlayer alloc] initWithContentsOfURL:url    error:&error];
[audioPlayer101  play];
[audioPlayer101 release];

audioPlayer101一旦创建就会被释放，因为系统不会自动保留它，释放lead会使播放停止。

如果您像使用代码一样使用instance.audioPlayerForPlay = audioPlayer101;，且audioPlayerForPlay的属性为strong，则播放将按实例保留，因此播放可以继续播放。你可以尝试设置audioPlayerForPlay to be弱`，之前的代码也不会播放。