問題播放音頻Iphone

Question

我只是想讓一個簡單的MP3播放器工作。我收到了一個我不太明白的錯誤。

我有AVAudioPlayer實例在我的.h文件聲明，我合成它在我的.m文件....

Undefined symbols: 
    ".objc_class_name_AVAudioPlayer", referenced from: 
     literal-pointer@__OBJC@__cls_refs@AVAudioPlayer in PromoTabOptionHome.o 
ld: symbol(s) not found 
collect2: ld returned 1 exit status 

我的.h文件的定義如下

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


@interface PromoTabOptionHome : UIViewController { 

    UIButton *playPause; 
    AVAudioPlayer* audioPlayer; 
    NSMutableString *audioPath; 
    BOOL playing; 

} 

@property(nonatomic,retain)UIButton *playPause; 
@property(nonatomic,retain)NSMutableString *audioPath; 
@property(nonatomic,retain)AVAudioPlayer *audioPlayer; 
-(id)initWithTabBar; 
@end 

而且我的執行文件是這樣的

#import "PromoTabOptionHome.h" 
@implementation PromoTabOptionHome 

@synthesize playPause; 
@synthesize audioPath; 
@synthesize audioPlayer; 

-(id) initWithTabBar { 
    if ([self init]) { 
     self.tabBarItem.image = [UIImage imageNamed:@"home.png"]; 

     // set the long name shown in the navigation bar 
     self.navigationItem.title=@"Nav Title"; 
    } 
    return self; 

} 


// Implement viewDidLoad to do additional setup after loading the view, typically from a nib. 
- (void)viewDidLoad { 
    [super viewDidLoad]; 

    playPause = [UIButton buttonWithType:UIButtonTypeCustom]; 
    playPause.frame = CGRectMake(-20,280, 100,100); 
    [playPause setImage:[UIImage imageNamed:@"play.png"] forState:UIControlStateNormal]; 
    [playPause addTarget:self action:@selector(buttonPushed:) 
      forControlEvents:UIControlEventTouchUpInside]; 
    [self.view addSubview:playPause]; 

    playing=NO; 

    NSURL *url = [NSURL fileURLWithPath:[NSString stringWithFormat:audioPath, [[NSBundle mainBundle] resourcePath]]]; 

    NSError *error; 
    audioPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL:url error:&error]; 
    //audioPlayer.numberOfLoops = -1; 

    if (audioPlayer == nil) 
     NSLog([error description]); 
    else 
     [audioPlayer play]; 
} 

- (void) buttonPushed:(id)sender 
{ 
    NSLog(@"It works!"); 

    switch (playing) { 
     case NO: 
      playing=YES; 
       [playPause setImage:[UIImage imageNamed:@"pause.png"] forState:UIControlStateNormal]; 
      break; 
     case YES: 
      playing=NO; 
       [playPause setImage:[UIImage imageNamed:@"play.png"] forState:UIControlStateNormal]; 
      break; 
     default: 
      break; 
    } 
} 

- (void)didReceiveMemoryWarning { 
    // Releases the view if it doesn't have a superview. 
    [super didReceiveMemoryWarning]; 

    // Release any cached data, images, etc that aren't in use. 
} 

- (void)viewDidUnload { 
    // Release any retained subviews of the main view. 
    // e.g. self.myOutlet = nil; 
} 


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


@end 

Answer 1

你的AVFoundation框架添加到您的項目？

通過右鍵單擊框架組這樣做，然後單擊添加>現有框架

Answer 2

你可能丟失的AVFoundation.framework項目中的參考。默認情況下不會添加此引用。您需要手動添加AVFoundation.framework。

1. 在組和文件 - >展開項目上鏈接二進制文件與庫
2. 右鍵
3. 選擇添加
4. 選擇現有框架 - >一覽彈出現有框架
5. 選擇AVFoundation.framework
6. 點擊添加

這應該解決您的問題。這個對我有用。