iPhone開發之AVAudioPlayer 音頻播放

首先，要給工程中添加音頻,首先要導入音頻的框架 AVFoundation.framework

然後新建一個類繼承於UIViewController, 我這裏就叫FirstVC.首先在 AppDelegate.m中初始化根視圖

//
//  AppDelegate.m
//  YinPinShiPin
//
//  Created by VincentXue on 12-9-3.
//  Copyright (c) 2012年 VincentXue. All rights reserved.
//

#import "AppDelegate.h"
#import "FirstVC.h"
@implementation AppDelegate

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

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    self.window = [[[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]] autorelease];
    // Override point for customization after application launch.
    
    FirstVC *firstVC = [[FirstVC alloc] init];
    self.window.rootViewController = firstVC;
    [firstVC release];
    
    self.window.backgroundColor = [UIColor whiteColor];
    [self.window makeKeyAndVisible];
    return YES;
}

然後在FirstVC.h中導入AVFoundation框架  

//
//  FirstVC.h
//  YinPinShiPin
//
//  Created by VincentXue on 12-9-3.
//  Copyright (c) 2012年 VincentXue. All rights reserved.
//

#import <UIKit/UIKit.h>

//要想使用封裝好的音頻類,導入框,導入類頭文件,缺一不可;
#import <AVFoundation/AVFoundation.h>

@interface FirstVC : UIViewController<AVAudioPlayerDelegate>
{
    AVAudioPlayer *avAudioPlayer;   //播放器player
    UIProgressView *progressV;      //播放進度
    UISlider *volumeSlider;         //聲音控制
    NSTimer *timer;                 //監控音頻播放進度
}

@end

然後在FirstVC.m裏的viewDidLoad方法裏填寫代碼   你需要導入一個音頻纔可以播放 像添加圖片一樣,直接拖到工程裏就可以了

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view.
    //初始化三個button
    UIButton *button = [UIButton buttonWithType:UIButtonTypeRoundedRect];
    [button setFrame:CGRectMake(100, 100, 60, 40)];
    [button setTitle:@"Play" forState:UIControlStateNormal];
    [button addTarget:self action:@selector(play) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:button];
    
    UIButton *button1 = [UIButton buttonWithType:UIButtonTypeRoundedRect];
    [button1 setFrame:CGRectMake(100, 150, 60, 40)];
    [button1 setTitle:@"pause" forState:UIControlStateNormal];
    [button1 addTarget:self action:@selector(pause) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:button1];
    
    UIButton *button2 = [UIButton buttonWithType:UIButtonTypeRoundedRect];
    [button2 setFrame:CGRectMake(100, 200, 60, 40)];
    [button2 setTitle:@"stop" forState:UIControlStateNormal];
    [button2 addTarget:self action:@selector(stop) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:button2];
    
    //從budle路徑下讀取音頻文件　　輕音樂 - 薩克斯回家 這個文件名是你的歌曲名字,mp3是你的音頻格式
    NSString *string = [[NSBundle mainBundle] pathForResource:@"輕音樂 - 薩克斯回家" ofType:@"mp3"];
    //把音頻文件轉換成url格式
    NSURL *url = [NSURL fileURLWithPath:string];
    //初始化音頻類 並且添加播放文件
    avAudioPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL:url error:nil];
    //設置代理
    avAudioPlayer.delegate = self;
    
    //設置初始音量大小
   // avAudioPlayer.volume = 1;
    
    //設置音樂播放次數  -1爲一直循環
    avAudioPlayer.numberOfLoops = -1;
    
    //預播放
    [avAudioPlayer prepareToPlay];
    
    //初始化一個播放進度條
    progressV = [[UIProgressView alloc] initWithFrame:CGRectMake(20, 50, 200, 20)];
    [self.view addSubview:progressV];
    [progressV release];
    
    //用NSTimer來監控音頻播放進度
    timer = [NSTimer scheduledTimerWithTimeInterval:0.1 target:self
                                                     selector:@selector(playProgress)
                                                     userInfo:nil repeats:YES];
    //初始化音量控制
    volumeSlider = [[UISlider alloc] initWithFrame:CGRectMake(20, 70, 200, 20)];
    [volumeSlider addTarget:self action:@selector(volumeChange)
                       forControlEvents:UIControlEventValueChanged];
    //設置最小音量
    volumeSlider.minimumValue = 0.0f;
    //設置最大音量
    volumeSlider.maximumValue = 10.0f;
    //初始化音量爲多少
    volumeSlider.value = 5.0f;
    
    [self.view addSubview:volumeSlider];
    [volumeSlider release];

    //聲音開關控件(靜音)
    UISwitch *swith = [[UISwitch alloc] initWithFrame:CGRectMake(100, 20, 60, 40)];
    [swith addTarget:self action:@selector(onOrOff:) forControlEvents:UIControlEventValueChanged];
    //默認狀態爲打開
    swith.on = YES;
    [self.view addSubview:swith];
    [swith  release];
}

相應的自定義方法代碼如下

//播放
- (void)play
{  
    [avAudioPlayer play];
}
    //暫停
- (void)pause
{
    [avAudioPlayer pause];
}
    //停止
- (void)stop
{
    avAudioPlayer.currentTime = 0;  //當前播放時間設置爲0
    [avAudioPlayer stop];
}
//播放進度條
- (void)playProgress
{
    //通過音頻播放時長的百分比,給progressview進行賦值;
    progressV.progress = avAudioPlayer.currentTime/avAudioPlayer.duration;
}
//聲音開關(是否靜音)
- (void)onOrOff:(UISwitch *)sender
{
    avAudioPlayer.volume = sender.on;
}

//播放音量控制
- (void)volumeChange
{
   avAudioPlayer.volume = volumeSlider.value;
}

//播放完成時調用的方法  (代理裏的方法),需要設置代理纔可以調用
- (void)audioPlayerDidFinishPlaying:(AVAudioPlayer *)player successfully:(BOOL)flag
{
    [timer invalidate]; //NSTimer暫停   invalidate  使...無效;
}

最後別忘了釋放內存

- (void)dealloc
{
    [avAudioPlayer release];
    [progressV release];
    [volumeSlider release];
    [timer release];
    [super dealloc];
}

當然,你也可以再定義一個UISlider來控制播放進度.