停止背景音乐

Question

我有这个有多个视图控制器的应用程序。在应用程序委托中，我进行了设置，以便应用程序完成启动后，背景音乐就会开始播放。但是，在另一个视图控制器上，我有一个播放这个视频的按钮。我的问题是当我播放电影时，背景音频与电影重叠。我的问题是，我如何在播放电影时停止音乐并在电影结束后播放音乐。 这是我的 app_delegate.h：

#import <UIKit/UIKit.h>
#import <AVFoundation/AVFoundation.h>

@interface App_Delegate : NSObject <UIApplicationDelegate> {

    UIWindow *window;
    UINavigationController *navigationController;
}

@property (nonatomic, retain) IBOutlet UIWindow *window;
@property (nonatomic, retain) IBOutlet UINavigationController *navigationController;

@end

这是我的 App_Delegate.m

#import "App_Delegate.h"
#import "RootViewController.h"


@implementation App_Delegate

@synthesize window;
@synthesize navigationController;


#pragma mark -
#pragma mark Application lifecycle

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {    

    {NSString* soundFilePath = [[NSBundle mainBundle] pathForResource:@"beethoven_sym_5_i" ofType:@"mp3"];
        NSURL* soundFileURL = [NSURL fileURLWithPath:soundFilePath];
        AVAudioPlayer* player = [[AVAudioPlayer alloc] initWithContentsOfURL:soundFileURL error:nil];
        player.numberOfLoops=-1;
        [player play];
    }


    // Override point for customization after application launch.

    // Set the navigation controller as the window's root view controller and display.
    self.window.rootViewController = self.navigationController;
    [self.window makeKeyAndVisible];

    return YES;
}


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


@end

我的 MovieViewController.h：

#import <UIKit/UIKit.h>
#import <MediaPlayer/MediaPlayer.h>
#import <AVFoundation/AVFoundation.h>

@interface MovieViewController : UIViewController {

    IBOutlet UIScrollView *sesamescroller;
}

- (IBAction)playsesamemovie:(id)sender;


@end

最后，我的 MovieViewController.m

#import "MovieViewController.h"


@interface MovieViewController ()

@end

@implementation MovieViewController

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
        // Custom initialization
    }
    return self;
}

- (void)viewDidLoad


- (void)viewDidUnload


- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
    return (interfaceOrientation == UIInterfaceOrientationPortrait);
}

- (IBAction)playsesamemovie:(id)sender {
    NSString *filepath   =   [[NSBundle mainBundle] pathForResource:@"How to make Sesame chicken" ofType:@"mp4"];
    NSURL    *fileURL    =   [NSURL fileURLWithPath:filepath];
    MPMoviePlayerController *moviePlayerController = [[MPMoviePlayerController alloc] initWithContentURL:fileURL];
    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(moviePlaybackComplete:)
                                                 name:MPMoviePlayerPlaybackDidFinishNotification
                                               object:moviePlayerController];
    [self.view addSubview:moviePlayerController.view];
    moviePlayerController.fullscreen = YES;
    [moviePlayerController play];
}


- (void)moviePlaybackComplete:(NSNotification *)notification
{
    MPMoviePlayerController *moviePlayerController = [notification object];
    [[NSNotificationCenter defaultCenter] removeObserver:self
                                                    name:MPMoviePlayerPlaybackDidFinishNotification
                                                  object:moviePlayerController];
    [moviePlayerController.view removeFromSuperview];
    [moviePlayerController release];
}

- (void)dealloc {
    [sesamescroller release];
    [super dealloc];
}
@end

Answer 1

您展示的代码有一个指向player 对象的局部变量。要控制播放器，其他代码需要能够找到它。像这样：

在App_Delegate.h:

@property (strong) AVAudioPlayer *player;

in App_Delegate.m：（这个下划线是从哪里来的？最不合常规的！）

self.player = [[AVAudioPlayer alloc] initWithContentsOfURL:soundFileURL error:nil];
self.player.numberOfLoops=-1;
[self.player play];

然后，无论你想控制它：

[((App_Delegate *)([UIApplication sharedApplication].delegate)).player pause];
// ...
[((App_Delegate *)([UIApplication sharedApplication].delegate)).player play];

Answer 2

 set scalling mode to your player

for Paused :
 [moviePlayerController setScalingMode:MPMoviePlaybackStatePaused];

 for Stopped:
 [moviePlayerController setScalingMode:MPMoviePlaybackStateStopped];

Answer 3

如果可能在 iOS 上，您可以使用脚本功能将消息发送到静音。我曾经在 Mac OS X 上这样做过，我曾经在其中通过另一个应用程序控制 iTunes。

Answer 4

首先在应用程序委托中添加歌曲开始

.h 应用程序委托

 #import <UIKit/UIKit.h>
 #import <AudioToolbox/AudioToolbox.h>
 #import <AVFoundation/AVFoundation.h>
 @class ViewController;
 @interface AppDelegate : UIResponder <UIApplicationDelegate,AVAudioPlayerDelegate>
{
    AVAudioPlayer *myAudioPlayer;
    NSDictionary *config;
   NSMutableArray *ARRAY;

}
-(void)stop;
@property(retain,nonatomic) NSDictionary *config;
@property (nonatomic, retain) AVAudioPlayer *myAudioPlayer;
@property (strong, nonatomic) UIWindow *window;

@property (strong, nonatomic) ViewController *viewController;

@end

.m 应用程序委托

  @implementation AppDelegate
  {
      AVAudioPlayer*  audioPlayer;
  }
  @synthesize myAudioPlayer;
   - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions: (NSDictionary *)launchOptions
  {
        audioPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL:[NSURL fileURLWithPath:path] error:&error];
        audioPlayer.delegate = self;
       [[AVAudioSession sharedInstance] setCategory:AVAudioSessionCategoryPlayback error:nil];
       [[AVAudioSession sharedInstance] setActive: YES error: nil];
       [[UIApplication sharedApplication] beginReceivingRemoteControlEvents];
      audioPlayer.numberOfLoops =  1;
      audioPlayer.delegate=self;
      [audioPlayer play];
 }
 -(void)stop
 {
     [audioPlayer stop];

 }
 -(void)star
 {
     [audioPlayer play];

 }

在应用程序中使用所需的启动和停止背景音乐时

直接调用这个方法-start和-stop

..它确实有效