过去三天我一直在拔头发来解决这个问题。我已经检查了大量的示例代码，阅读了大量的教程，并使用Google搜索并检查了很多关于stackoverflow的问题和答案，但我仍然无法解决问题。有几个类似的问题，如this或this，但他们也没有任何解决方案。
关于我的项目的一点点：
我有NIKMasterViewController和NIKDetailViewController。在第一个中，我在表格视图中有一个音频文件列表;选择一行，它会导航到NIKDetailViewController，用户可以在其中查看有关该文件的一些信息并播放音频文件。
我在AVAudioPlayer中定义了NIKMasterViewController属性，并将其设置为：
NIKMasterViewController.h：
@property (nonatomic, strong) AVAudioPlayer *audioPlayer;
NIKMasterViewController.m：
@synthesize audioPlayer;
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
if ([[segue identifier] isEqualToString:@"showDetail"])
{
NSIndexPath *indexPath = [self.tableView indexPathForCell:sender];
NIKDetailViewController *detailViewController = (NIKDetailViewController *) segue.destinationViewController;
[detailViewController setAudioPlayer:audioPlayer];
[detailViewController setFeedEntry:[[[self feedParser] feedItems] objectAtIndex:indexPath.row]];
} else {
NSLog(@"Segue Identifier: %@", segue.identifier);
}
}
这就是AVAudioPlayer中NIKMasterViewController的全部内容。现在我的NIKDetailViewController我有AVAudioPlayer的另一个属性：
NIKDetailViewController.h：
@property (nonatomic, strong) AVAudioPlayer *audioPlayer;
现在在我的.m文件中，我有一个名为streamAudio的方法，在viewDidLoad中调用以准备音频播放，我有一个if条件，要求检查{ {1}}是audioPlayer，如果没有，如果nill为真，那么audioPlayer.isPlaying是播放器，但它永远不会被调用，当我导航回Master VC时点击另一行播放另一个文件，第二个文件在播放第一个文件时开始播放，一切都混淆了。
任何帮助都会得到真正的赞赏，因为我几乎要在几小时后无法解决这个问题后停止编程！
stop：
NIKDetailViewController.m 注意：我已尝试将详细信息VC中的属性设置为@synthesize audioPlayer;
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
// Custom initialization
selectedItem = [[NSString alloc]init];
}
return self;
}
#pragma mark - Managing the Audio Playback
- (IBAction)togglePlayingState:(id)button
{
//Handle the button pressing
[self togglePlayPause];
}
- (void)playAudio
{
//Play the audio and set the button to represent the audio is playing
[audioPlayer play];
[playPauseButton setImage:[UIImage imageNamed:@"player_pause"] forState:UIControlStateNormal];
}
- (void)pauseAudio
{
//Pause the audio and set the button to represent the audio is paused
[audioPlayer pause];
[playPauseButton setImage:[UIImage imageNamed:@"player_play"] forState:UIControlStateNormal];
}
- (void)togglePlayPause
{
//Toggle if the music is playing or paused
if (!audioPlayer.playing)
{
[self playAudio];
}
else if (audioPlayer.playing)
{
[self pauseAudio];
}
}
- (void)streamAudio
{
currentFileName = [[feedEntry podcastDownloadURL] lastPathComponent];
NSString* documentPath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
NSString* path = [documentPath stringByAppendingPathComponent:currentFileName];
NSURL* audioURL = [NSURL fileURLWithPath: path];
if (audioPlayer != nil)
{
if (audioPlayer.isPlaying)
{
[audioPlayer stop]; //THIS IS NEVER CALLED
}
audioPlayer = nil; //THIS IS NEVER CALLED
}
audioPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL:audioURL error:nil];
// Set a timer which keep getting the current music time and update the UISlider in 1 sec interval
playbackTimer = [NSTimer scheduledTimerWithTimeInterval:1.0 target:self selector:@selector(updateSlider) userInfo:nil repeats:YES];
// Set the maximum value of the UISlider
seekSlider.maximumValue = audioPlayer.duration;
currentTime.text = [NSString stringWithFormat:@"%d:%02d", (int)audioPlayer.currentTime / 60, (int)audioPlayer.currentTime % 60, nil];
remainingTime.text = [NSString stringWithFormat:@"%d:%02d", (int)(audioPlayer.duration - audioPlayer.currentTime) / 60, (int)(audioPlayer.duration - audioPlayer.currentTime) % 60, nil];
// Set the valueChanged target
[seekSlider addTarget:self action:@selector(sliderChanged:) forControlEvents:UIControlEventValueChanged];
audioPlayer.delegate = self;
[audioPlayer prepareToPlay]; //Add the audio to the memory.
}
- (void)updateSlider
{
// Update the slider about the music time
seekSlider.value = audioPlayer.currentTime;
}
- (IBAction)sliderChanged:(UISlider *)sender {
// Fast skip the music when user scrolls the slider
[audioPlayer stop];
[audioPlayer setCurrentTime:seekSlider.value];
audioPlayer.delegate = self;
[audioPlayer prepareToPlay];
[audioPlayer play];
}
// Stop the timer when the music is finished (Need to implement the AVAudioPlayerDelegate in the Controller header)
- (void)audioPlayerDidFinishPlaying:(AVAudioPlayer *)player successfully:(BOOL)flag {
// Music completed
if (flag) {
[playbackTimer invalidate];
}
}
- (IBAction)forwardAudio:(id)sender
{
int currentTime = [audioPlayer currentTime];
[audioPlayer setCurrentTime:currentTime+10];
}
- (IBAction)rewindAudio:(id)sender
{
int currentTime = [audioPlayer currentTime];
[audioPlayer setCurrentTime:currentTime-10];
}
//Make sure we can recieve remote control events
- (BOOL)canBecomeFirstResponder {
return YES;
}
- (void)remoteControlReceivedWithEvent:(UIEvent *)event {
//if it is a remote control event handle it correctly
if (event.type == UIEventTypeRemoteControl) {
if (event.subtype == UIEventSubtypeRemoteControlPlay) {
[self playAudio];
} else if (event.subtype == UIEventSubtypeRemoteControlPause) {
[self pauseAudio];
} else if (event.subtype == UIEventSubtypeRemoteControlTogglePlayPause) {
[self togglePlayPause];
}
}
}
#pragma mark - view life cycle
- (void)viewDidAppear:(BOOL)animated {
[super viewDidAppear:animated];
//Once the view has loaded then we can register to begin recieving controls and we can become the first responder
[[UIApplication sharedApplication] beginReceivingRemoteControlEvents];
[self becomeFirstResponder];
}
- (void)viewWillDisappear:(BOOL)animated {
[super viewWillDisappear:animated];
//End recieving events
[[UIApplication sharedApplication] endReceivingRemoteControlEvents];
[self resignFirstResponder];
}
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
[self streamAudio];
//Make sure the system follows our playback status - to support the playback when the app enters the background mode.
[[AVAudioSession sharedInstance] setCategory:AVAudioSessionCategoryPlayback error:nil];
[[AVAudioSession sharedInstance] setActive: YES error: nil];
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
@end
，但之后，我收到警告，并且在播放文件之前该属性已释放。
答案 0 :(得分：1)
所以......我可以通过创建singleton的{{1}}来解决此问题。这是如何：
audioplayer类中删除了与audioPlayer相关的所有代码，其中包含NIKMasterViewController声明并在audioPlayer中设置。 prepareForSegue的新类。在NIKAudioPlayer：
NIKAudioPlayer.h在#import <Foundation/Foundation.h>
#import <AVFoundation/AVFoundation.h>
@interface NIKAudioPlayer : NSObject <AVAudioPlayerDelegate>
{
AVAudioPlayer *currentPlayer;
}
@property (nonatomic, strong) AVAudioPlayer *currentPlayer;
+(NIKAudioPlayer *) sharedPlayer;
-(void)playURL:(NSURL*)url;
@end
：
NIKAudioPlayer.m现在，在我需要播放音频文件的代码中的其他地方（我的情况为#import "NIKAudioPlayer.h"
@implementation NIKAudioPlayer
@synthesize currentPlayer;
+(NIKAudioPlayer *) sharedPlayer
{
static NIKAudioPlayer* sharedPlayer;
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
sharedPlayer = [[NIKAudioPlayer alloc] init];
});
return sharedPlayer;
}
-(void)playURL:(NSURL*)url
{
[currentPlayer stop];
currentPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL:url error:nil];
[currentPlayer prepareToPlay];
}
@end
），我从NIKDetailViewController调用sharedPlayer：
NIKAudioPlayer简而言之，将[[NIKPlayer sharedPlayer] playURL:audioURL];
[[NIKPlayer sharedPlayer].currentPlayer prepareToPlay];
中的所有audioPlayer替换为NIKDetailViewController，甚至将其投射并随处使用：
[NIKPlayer sharedPlayer].currentPlayer