为什么在标签之间移动，重新初始化歌曲？

我有一个在线广播播放器与选项卡页脚function。 第一个选项卡包含播放器，第二个网站和第三个消息框。 现在发生的事情是，当我在第一个页脚播放歌曲，然后去另一个页脚，并返回到第一个页脚，歌曲再次开始。 这里是代码：

FirstViewController.m

#import "FirstViewController.h" CM_EXPORT const CMTime kCMTimeZero; @interface FirstViewController () @end @implementation FirstViewController @synthesize metadatas; @synthesize toggleButton; @synthesize slider; @synthesize mpVolumeView = _mpVolumeView; @synthesize viewVolume; - (void)viewDidLoad { toggleIsOn=TRUE; MPVolumeView *volumeView = [[MPVolumeView alloc] initWithFrame:self.viewVolume.bounds] ; [self.viewVolume addSubview:volumeView]; [volumeView sizeToFit]; [[UIApplication sharedApplication] beginReceivingRemoteControlEvents]; } - (void)didReceiveMemoryWarning { [super didReceiveMemoryWarning]; } -(IBAction)playButtonPressed:(id)sender { NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults]; [defaults setBool:TRUE forKey:@"FirstPlay"]; [defaults setBool:YES forKey:@"alertShown"]; if(toggleIsOn){ toggleIsOn=!toggleIsOn; player = nil; NSString *stringurl = @""; stringurl = @"http://majestic.wavestreamer.com:6221/listen.pls"; NSURL *url = [NSURL URLWithString:stringurl]; asset = [AVURLAsset URLAssetWithURL:url options:nil]; playerItem = [AVPlayerItem playerItemWithAsset:asset]; player = [AVPlayer playerWithPlayerItem:playerItem]; player.actionAtItemEnd = AVPlayerActionAtItemEndNone; [playerItem addObserver:self forKeyPath:@"timedMetadata" options:NSKeyValueObservingOptionNew context:nil]; [playerItem addObserver:self forKeyPath:@"status" options:NSKeyValueObservingOptionNew context:nil]; [player play]; NSNotificationCenter *center = [NSNotificationCenter defaultCenter]; [center addObserver:self selector:@selector(audioSessionInterrupted:) name:AVAudioSessionInterruptionNotification object:nil]; [self.toggleButton setImage:[UIImage imageNamed:@"reload.png"] forState:UIControlStateNormal]; [[AVAudioSession sharedInstance] setCategory:AVAudioSessionCategoryPlayback error:nil]; [[AVAudioSession sharedInstance] setActive: YES error: nil]; [[UIApplication sharedApplication] beginReceivingRemoteControlEvents]; } else { [self.toggleButton setImage:[UIImage imageNamed:@"playMusic.png"] forState:UIControlStateNormal]; self->player.rate=0.0; toggleIsOn=!toggleIsOn; } } - (void)audioSessionInterrupted:(NSNotification *)notification { NSNumber *interruptionType = [[notification userInfo] objectForKey:AVAudioSessionInterruptionTypeKey]; NSNumber *interruptionOption = [[notification userInfo] objectForKey:AVAudioSessionInterruptionOptionKey]; switch (interruptionType.unsignedIntegerValue) { case AVAudioSessionInterruptionTypeBegan:{ // [self.toggleButton setImage:[UIImage imageNamed:@"playMusic.png"] forState:UIControlStateNormal]; // • Audio has stopped, already inactive // • Change state of UI, etc., to reflect non-playing state } break; case AVAudioSessionInterruptionTypeEnded:{ // • Make session active // • Update user interface // • AVAudioSessionInterruptionOptionShouldResume option if (interruptionOption.unsignedIntegerValue == AVAudioSessionInterruptionOptionShouldResume) { // Here you should continue playback. [player play]; } } break; default: break; } } - (void)audioPlayerBeginInterruption:(AVAudioPlayer *)audioPlayer { [player pause]; } -(void)audioRecorderEndInterruption:(AVAudioRecorder *)audioPlayer { [player play]; } - (void)viewWillAppear:(BOOL)animated { [super viewWillAppear:animated]; NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults]; [defaults setBool:TRUE forKey:@"alertShown"]; [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(checkNetworkStatus:) name:kReachabilityChangedNotification object:nil]; internetReachable = [Reachability reachabilityForInternetConnection]; [internetReachable startNotifier]; // check if a pathway to a random host exists hostReachable = [Reachability reachabilityWithHostName:@"www.apple.com"]; [hostReachable startNotifier]; } - (void)viewDidAppear:(BOOL)animated { [super viewDidAppear:animated]; [[UIApplication sharedApplication] beginReceivingRemoteControlEvents]; [self becomeFirstResponder]; } - (void)viewWillDisappear:(BOOL)animated { [super viewWillDisappear:animated]; [[UIApplication sharedApplication] endReceivingRemoteControlEvents]; [self resignFirstResponder]; } - (void)viewDidDisappear:(BOOL)animated { [super viewDidDisappear:animated]; } - (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation { return (interfaceOrientation != UIInterfaceOrientationPortraitUpsideDown); } - (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context { [playerItem removeObserver:self forKeyPath:keyPath]; if ([keyPath isEqualToString:@"status"]) { AVPlayerItem *pItem = (AVPlayerItem *)object; if (pItem.status == AVPlayerItemStatusReadyToPlay) { metadatas.text = @""; } } if ([keyPath isEqualToString:@"timedMetadata"]) { for (AVAssetTrack *track in playerItem.tracks) { for (AVPlayerItemTrack *item in player.currentItem.tracks) { if ([item.assetTrack.mediaType isEqual:AVMediaTypeAudio]) { NSArray *meta = [playerItem timedMetadata]; for (AVMetadataItem *metaItem in meta) { NSString *source = metaItem.stringValue; metadatas.text = source; } } } } } [self.toggleButton setImage:[UIImage imageNamed:toggleIsOn ? @"playMusic.png" :@"stop.png"] forState:UIControlStateNormal]; } -(IBAction) sliderChanged:(id)sender { player.volume = slider.value; } -(void) checkNetworkStatus:(NSNotification *)notice { // called after network status changes NetworkStatus internetStatus = [internetReachable currentReachabilityStatus]; NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults]; switch (internetStatus) { case NotReachable: { NSLog(@"The internet is down."); NSLog(@"%d",[defaults boolForKey:@"alertShown"]); BOOL isAlertShown = [defaults boolForKey:@"alertShown"]; if(isAlertShown) { [self showAlert]; } break; } case ReachableViaWiFi: { NSLog(@"The internet is working via WIFI."); BOOL isFirstTimePlayed = [defaults boolForKey:@"FirstPlay"]; if(isFirstTimePlayed) { [self playButtonPressed:nil]; } break; } case ReachableViaWWAN: { NSLog(@"The internet is working via WWAN."); [self playButtonPressed:nil]; break; } } } -(void)showAlert { NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults]; [defaults setBool:FALSE forKey:@"alertShown"]; UIAlertView *alert = [[UIAlertView alloc] initWithTitle: @"Alert" message: @"You have lost data connectivity. Please wait while we try to establish the connection again." delegate: nil cancelButtonTitle:@"OK" otherButtonTitles:nil]; [alert show]; } - (NSUInteger)supportedInterfaceOrientations{ return UIInterfaceOrientationMaskPortrait; } @end 

SecondViewController.m

 #import "SecondViewController.h" #import "MBProgressHUD.h" @interface SecondViewController () @end @implementation SecondViewController - (void)viewDidLoad { [super viewDidLoad]; webView = [[UIWebView alloc] init]; [webView setFrame:self.view.frame]; [webView loadRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:@"http://www.radiomalayalam.net"]]]; [self.view addSubview:webView]; CGSize contentSize = webView.scrollView.contentSize; CGSize viewSize = self.view.bounds.size; float rw = viewSize.width / contentSize.width; webView.scrollView.minimumZoomScale = rw; webView.scrollView.maximumZoomScale = rw; webView.scrollView.zoomScale = rw; webView.scalesPageToFit = YES; [webView setDelegate:self]; MBProgressHUD *hud = [MBProgressHUD showHUDAddedTo:self.view animated:YES]; hud.labelText = @"Loading"; // you can implement any int/float value in context of what scale you want to zoom in or out } - (void)didReceiveMemoryWarning { [super didReceiveMemoryWarning]; // Dispose of any resources that can be recreated. } - (void)twoFingerPinch:(UIPinchGestureRecognizer *)recognizer { NSLog(@"Pinch scale: %f", recognizer.scale); CGAffineTransform transform = CGAffineTransformMakeScale(recognizer.scale, recognizer.scale); // you can implement any int/float value in context of what scale you want to zoom in or out webView.transform = transform; } -(void)webViewDidFinishLoad:(UIWebView *)webView { [MBProgressHUD hideHUDForView:self.view animated:YES]; } - (NSUInteger)supportedInterfaceOrientations{ return UIInterfaceOrientationMaskPortrait; } @end 

ThirdViewController.m

 #import "ThirdViewController.h" @interface ThirdViewController () @end @implementation ThirdViewController @synthesize mBodyText,mSubjectLabel; - (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil { self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil]; if (self) { [mBodyText setDelegate:self ]; [mSubjectLabel setDelegate:self]; } return self; } - (IBAction)hidekeyBoard:(id)sender { [mSubjectLabel resignFirstResponder]; } - (IBAction)hidekeyBoard2:(id)sender { } - (void)viewDidLoad { [super viewDidLoad]; // Do any additional setup after loading the view. } - (void)registerForKeyboardNotifications { [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillBeShown:) name:UIKeyboardWillShowNotification object:nil]; [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillBeHidden:) name:UIKeyboardWillHideNotification object:nil]; } - (void)keyboardWillBeShown:(NSNotification*)aNotification { CGRect backgroundViewFrame = self.view.frame; if (backgroundViewFrame.origin.y >= 0) { [UIView beginAnimations:nil context:NULL]; [UIView setAnimationDuration:0.3]; backgroundViewFrame.origin.y -= 100; self.view.frame = backgroundViewFrame; [UIView commitAnimations]; } } - (void)keyboardWillBeHidden:(NSNotification*)aNotification { CGRect backgroundViewFrame = self.view.frame; // if (backgroundViewFrame.origin.y < 130) { [UIView beginAnimations:nil context:NULL]; [UIView setAnimationDuration:0.3]; backgroundViewFrame.origin.y += 100; self.view.frame = backgroundViewFrame; [UIView commitAnimations]; } } - (void)textViewDidChange:(UITextView *)textView { } - (void) resignIfResponder { if ([mBodyText isFirstResponder]) [mBodyText resignFirstResponder]; } - (void)didReceiveMemoryWarning { [super didReceiveMemoryWarning]; // Dispose of any resources that can be recreated. } - (IBAction)onSendMail:(id)sender { NSLog(@"%@",mSubjectLabel.text); NSMutableString *subject = [NSMutableString string]; [subject appendString:mSubjectLabel.text]; NSMutableString *mailbody = [NSMutableString string]; [mailbody appendString:mBodyText.text]; NSString *recipients = [NSString stringWithFormat:@"mailto:[e-mail]?&subject=%@!",subject]; NSString *body = [NSString stringWithFormat:@"&body=%@!",mailbody];; NSString *emailString = [NSString stringWithFormat:@"%@%@", recipients, body]; emailString = [emailString stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]; if ([[UIApplication sharedApplication] canOpenURL:[ NSURL URLWithString:@"mailto:"]]) { NSLog(@"Can Send"); [[UIApplication sharedApplication] openURL:[NSURL URLWithString:emailString]]; } } - (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event { UITouch *touch = [[event allTouches] anyObject]; if (![[touch view] isKindOfClass:[UITextField class]]) { [self.view endEditing:YES]; } [super touchesBegan:touches withEvent:event]; } - (NSUInteger)supportedInterfaceOrientations{ return UIInterfaceOrientationMaskPortrait; } @end 

请问是否需要粘贴更多的文件。 我无法理解如何删除重新开始的歌曲。 请帮忙。 感谢名单。