如何让我的两个音频播放器同时播放两首不同的歌曲

Question

好的，所以我会尽力解释。我的应用程序有两个音频播放器，我希望能够从我的音乐库中播放每个播放器的歌曲。我遇到的问题是，当我选择第一首歌播放时，它是有效的，然后当我选择另一首歌时，它会关闭第一首歌，两个音频播放器都只能播放选择的歌曲。如何让音频播放器播放两首不同的歌曲？这是我目前拥有的代码：

 //EDITED CODE: 
class GameScene: SKScene, MPMediaPickerControllerDelegate, AVAudioPlayerDelegate {
var mediaPicker: MPMediaPickerController?
var mediaPicker2: MPMediaPickerController?
var music2 = MPMediaItem()
var music = MPMediaItem()
var musicPlayer2 = AVAudioPlayer()
var musicPlayer = AVAudioPlayer()

func mediaPicker(mediaPicker: MPMediaPickerController, didPickMediaItems mediaItemCollection: MPMediaItemCollection) {
mediaPicker.dismissViewControllerAnimated(true, completion: nil)
let aMediaItem = mediaItemCollection.items[0] as MPMediaItem
music = aMediaItem
NSLog("(aMediaItem.title)selected")

let url: NSURL = (music.valueForProperty(MPMediaItemPropertyAssetURL) as? NSURL)!
    do {
        musicPlayer = try AVAudioPlayer(contentsOfURL: url)
    } catch {
        return
    }
        musicPlayer.pause()
        leftPlayButton.hidden = false


if mediaItemCollection.items.count > 1 {
    let aMediaItem2 = mediaItemCollection.items[1] as MPMediaItem
    music2 = aMediaItem2
    let url2: NSURL = (music2.valueForProperty(MPMediaItemPropertyAssetURL) as? NSURL)!
    do {
        musicPlayer2 = try AVAudioPlayer(contentsOfURL: url2)
    } catch {
        return
    }
    musicPlayer2.pause()
    rightPlayButton.hidden = false
}
 }
            if node.name == "addmusictoleft" {
            mediaPicker = MPMediaPickerController(mediaTypes: .Music)
            if let picker2 = mediaPicker{

                print("Successfully open media picker Left")
                picker2.delegate = self
                picker2.allowsPickingMultipleItems = true
                picker2.showsCloudItems = false
                picker2.prompt = "Pick a song for left player"
                self.view?.window?.rootViewController!.presentViewController(picker2, animated: true, completion: nil)
            } else {
                print("PICKER WONT OPEN")
            }
        }

            if node.name == "addmusictoright" {
            mediaPicker2 = MPMediaPickerController(mediaTypes: .Music)
            if let picker = mediaPicker2{

                print("Successfully open media picker Right")
                picker.delegate = self
                picker.allowsPickingMultipleItems = false
                picker.showsCloudItems = false
                picker.prompt = "Pick a song for right player"
                self.view?.window?.rootViewController!.presentViewController(picker, animated: true, completion: nil)
            } else {
                print("PICKER WONT OPEN")
            }

        }

Answer 1

我做了一个演示项目，它在我的iPad上运行良好。这是我的密码。

ViewController.h

#import <UIKit/UIKit.h>
#import <MediaPlayer/MediaPlayer.h>
#import <AVFoundation/AVFoundation.h>
@interface ViewController : UIViewController<MPMediaPickerControllerDelegate,AVAudioPlayerDelegate>

@end

ViewController.m

#import "ViewController.h"

@interface ViewController (){
int counter;
}
@property AVAudioPlayer *avAudioPlayer;
@property AVAudioPlayer *avAudioPlayer2;
@end
@implementation ViewController 
- (void)viewDidLoad {
[super viewDidLoad];

counter = 0;
self.avAudioPlayer.delegate = self;
self.avAudioPlayer2.delegate = self;
UIButton *button1 = [[UIButton alloc]initWithFrame:CGRectMake(120, 50, 80, 30)];
[button1 addTarget:self action:@selector(button1Click:) forControlEvents:UIControlEventTouchUpInside];
button1.backgroundColor = [UIColor yellowColor];
[button1 setTitle:@"play" forState:UIControlStateNormal];
[self.view addSubview:button1];

UIButton *button2 = [[UIButton alloc]initWithFrame:CGRectMake(120, 120, 80, 30)];
[button2 addTarget:self action:@selector(button2Click:) forControlEvents:UIControlEventTouchUpInside];
button2.backgroundColor = [UIColor yellowColor];
[button2 setTitle:@"Stop" forState:UIControlStateNormal];
[self.view addSubview:button2];
// Do any additional setup after loading the view, typically from a nib.
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
-(void)button2Click : (id)sender {
if (counter == 0) {
    [self.avAudioPlayer stop];
}
if (counter == 1) {
    [self.avAudioPlayer2 stop];
}

counter ++;
 }
-(void)button1Click : (id)sender {
MPMediaPickerController *mediaPicker = [[MPMediaPickerController alloc] initWithMediaTypes: MPMediaTypeMusic];
mediaPicker.delegate = self;
mediaPicker.allowsPickingMultipleItems = YES;
mediaPicker.prompt = @"Select songs to play";
mediaPicker.showsCloudItems = NO;
[self presentViewController:mediaPicker animated:YES completion:nil];
}
-(void)mediaPicker:(MPMediaPickerController *)mediaPicker didPickMediaItems:(MPMediaItemCollection *)mediaItemCollection {
  [self dismissViewControllerAnimated:YES completion:nil];

MPMediaItem *item = [[mediaItemCollection items]objectAtIndex:0];
NSURL *myURL = [item valueForProperty:MPMediaItemPropertyAssetURL];

NSError *err1;

self.avAudioPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL:myURL error:&err1];

if (err1) {
    NSLog(@"@err1 : %@",[err1 localizedDescription]);
}

[self.avAudioPlayer play];

if ([mediaItemCollection items].count >1) {
    MPMediaItem *item2 = [[mediaItemCollection items]objectAtIndex:1];
    NSURL *myURL2 = [item2 valueForProperty:MPMediaItemPropertyAssetURL];
    NSError *err2;
    self.avAudioPlayer2 = [[AVAudioPlayer alloc]initWithContentsOfURL:myURL2 error:&err2];
    if (err2) {
        NSLog(@"err2 : %@",[err2 localizedDescription]);
    }
    [self.avAudioPlayer2 play];
}
 // NSLog(@"mediaitemCollection : %@",[mediaItemCollection items]);

}
-(void)mediaPickerDidCancel:(MPMediaPickerController *)mediaPicker {
[self dismissViewControllerAnimated:YES completion:nil ];
}
@end

单击播放按钮并选择两个音乐文件，因为我们将allowsPickingMultipleItems设置为YES。

它在我的ipad上运行良好。如果需要，请将其转换为swift。我认为这不是一项困难的任务。

希望这能解决您的问题。：）