如何创建像 pandora 应用程序这样的音频播放器应用程序？

Question

我创建了一个从本地播放多个音频文件的应用程序。音频文件很长。音频播放器为用户提供以下选项：

• 前进、
• 后退、
• 下一曲目、
• 上一曲目，

我计划使用 AvAudioPlayer，以便我可以长时间播放音频。当我更改音频文件时，即按下一曲目音频。音频播放器实例没有被释放。此问题仅出现几次。请帮我..！！我无能为力..

下一曲目按钮 IBAction 方法

- (IBAction) nextTrackPressed
{
    [audioPlay stopAudio];
    if (audioPlay) {
        audioPlay = nil;
        [audioPlay release];
    }

    appDelegate.trackSelected += 1; 
    [self intiNewAudioFile];
    [self play];
}

Initializing audio file through below method

-(void) intiNewAudioFile
{
    NSAutoreleasePool *subPool = [[NSAutoreleasePool alloc] init];

    NSString *filePath = [[NSString alloc] init]; 

    trackObject = [appDelegate.trackDetailArray objectAtIndex:appDelegate.trackSelected];
    NSLog(@"%@",trackObject.trackName);
    // Get the file path to the song to play.
    filePath = [[NSBundle mainBundle] pathForResource:trackObject.trackName ofType:@"mp3"];

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

    if (audioPlay) {
        audioPlay = nil;
        [audioPlay release];
    }

    audioPlay = [[AudioPlayerClass alloc] init];
    [audioPlay initAudioWithUrl:fileURL];

    [filePath release];
    [fileURL release];
    [subPool release];
}

AudioPlayerClass 实现

#import "AudioPlayerClass.h"


@implementation AudioPlayerClass

- (void) initAudioWithUrl: (NSURL *) url
{

    curAudioPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL:url error:nil];
    [curAudioPlayer setDelegate:self];
    [curAudioPlayer prepareToPlay];
}

- (void) playAudio
{
    [curAudioPlayer play];
}

- (void) pauseAudio
{
    [curAudioPlayer pause];
}

- (void) stopAudio
{
    [curAudioPlayer stop];
}

- (BOOL) isAudioPlaying
{
    return curAudioPlayer.playing;
}

- (void) setAudiowithCurrentTime:(NSInteger) time
{
    curAudioPlayer.currentTime = time;
}

- (NSInteger) getAudioFileDuration
{
    return curAudioPlayer.duration;
}

- (NSInteger) getAudioCurrentTime
{
    return curAudioPlayer.currentTime;
}

- (void) releasePlayer
{
    [curAudioPlayer release];
}

- (void)dealloc {
    [curAudioPlayer release];
    [super dealloc];
}

@end

Answer 1

你的问题在这里：

if (audioPlay) {
        audioPlay = nil;
        [audioPlay release];
    }

你在调用release之前将audioPlay设置为nil，这意味着release消息被发送到nil。您需要颠倒这两行的顺序。

if (audioPlay) {
        [audioPlay release];
         audioPlay = nil;
    }