1. 播放mp3需要导入框架，AVFoundation支持音频文件（.caf、.aif、.wav、.wmv和.mp3）的播放。
#import <AVFoundation/AVFoundation.h>//音频播放框架
步骤：
a.声明一个音频播放对象：
{ AVAudioPlayer *_player; }
b.用一个支持的文件路径来初始化_player: (据说只能播放本地文件，像酷我等音乐软件应该是播放前下载到本地，然后进行播放的，因为在用酷我时，隔断时间就会提示我内存过大，请清理，应该就清理下载到到本地的音频文件)
NSString *path=[[NSBundle mainBundle]pathForResource:@"纯音乐-The True That You Leave" ofType:@"mp3"]; _player=[[AVAudioPlayer alloc]initWithContentsOfURL:[NSURL fileURLWithPath:path] error:nil]; [_player prepareToPlay]; [_player play]; //[_player pause];暂停 //[_player stop];停止 _player.volume=1;//音量 0.0-1.0
c. 如果想看播放时间可以注册一个定时器：
[NSTimer scheduledTimerWithTimeInterval:0.2 target:self selector:@selector(player) userInfo:nil repeats:YES];
NSLog(@"音频当前时间%lf",_player.currentTime);//音频当前时间 NSLog(@"音频总时间%lf",_player.duration);//音频总时间
d. 这样就实现了，如果想加个进度条，可以用UISlider: 下面这个是从Xib中拖出来的
@property (weak, nonatomic) IBOutlet UISlider *musicPlaySlider;
//更新时间进度条这样做
self.musicPlaySlider.value = (float)_player.currentTime/_player.duration;
//想移动UISlider 从指定那个时刻开始播放这样做
[self.musicPlaySlider addTarget:self action:@selector(moveMusicPlaySlider:) forControlEvents:UIControlEventValueChanged];
然后实现moveMusicPlaySlider：方法：
-(void)moveMusicPlaySlider:(UISlider *)sender{
NSLog(@"slider改变%f",sender.value);
self.musicPlaySlider.value = sender.value;
[_player stop];
_player.currentTime = _player.duration * sender.value;//给指定位置播放
[_player play];
}
音乐进度条3方应该很好找吧...
2. 播放mp4需要导入
#import <MediaPlayer/MediaPlayer.h>
步骤：
a. 声明一个视频播放器控制器
@property (nonatomic,strong) MPMoviePlayerController *moviePlayer;
b. 初始化moviePlayer可以放到懒加载：
-(MPMoviePlayerController *)moviePlayer { if (!_moviePlayer) { NSURL *url = [self getFileUrl]; _moviePlayer = [[MPMoviePlayerController alloc]initWithContentURL:url]; _moviePlayer.view.frame = self.view.bounds; _moviePlayer.view.autoresizingMask = UIViewAutoresizingFlexibleWidth|UIViewAutoresizingFlexibleHeight; [self.view addSubview:_moviePlayer.view]; } return _moviePlayer; }
c. 开始播放：
//播放 [self.moviePlayer play];
如果想看播放状态，截屏等 可以写一个方法注册通知：
-(void)addNotification {
NSNotificationCenter *notificationCenter = [NSNotificationCenter defaultCenter];
[notificationCenter addObserver:self selector:@selector(mediaPlayerPlaybackStateChange:) name:MPMoviePlayerPlaybackStateDidChangeNotification object:self.moviePlayer];
[notificationCenter addObserver:self selector:@selector(mediaPlayerPlaybackFinished:) name:MPMoviePlayerPlaybackDidFinishNotification object:self.moviePlayer];
//缩略图截屏完成
[notificationCenter addObserver:self selector:@selector(mediaPlayerThumbnailRequestFinished:) name:MPMoviePlayerThumbnailImageRequestDidFinishNotification object:self.moviePlayer];
}
然后这个方法里查看播放状态：
-(void)mediaPlayerPlaybackStateChange:(NSNotification *)notification {
/*
MPMoviePlaybackStateStopped,
MPMoviePlaybackStatePlaying,
MPMoviePlaybackStatePaused,
MPMoviePlaybackStateInterrupted,
MPMoviePlaybackStateSeekingForward,
MPMoviePlaybackStateSeekingBackward
*/
switch (self.moviePlayer.playbackState) {
case MPMoviePlaybackStatePlaying:
NSLog(@"playing...");
break;
case MPMoviePlaybackStatePaused:
NSLog(@"paused...");
break;
case MPMoviePlaybackStateStopped:
NSLog(@"stop...");
break;
default:
NSLog(@"playsatus...%li",self.moviePlayer.playbackState);
break;
}
}
如果想播放时指定时间点截图可以这样做：
//获取2.0s时刻缩略图
[self.moviePlayer requestThumbnailImagesAtTimes:@[@2.0] timeOption:MPMovieTimeOptionNearestKeyFrame];
然后在上面通知里的方法处理截图：
// 缩略图请求完成,此方法每次截图成功都会调用一次
-(void)mediaPlayerThumbnailRequestFinished:(NSNotification *)notification{
/*
{name = MPMoviePlayerThumbnailImageRequestDidFinishNotification; object = <MPMoviePlayerController: 0x608000004ba0>; userInfo = {
MPMoviePlayerThumbnailImageKey = "<UIImage: 0x6080000914e0>, {640, 352}";
MPMoviePlayerThumbnailTimeKey = 0;
}}
*/
NSLog(@"视频截图完成...%@",notification);
UIImage *image=notification.userInfo[MPMoviePlayerThumbnailImageKey];
//保存图片到相册(首次调用会请求用户获得访问相册权限)
UIImageWriteToSavedPhotosAlbum(image, nil, nil, nil);
//保存截图会暂停播放，继续
if (self.moviePlayer.playbackState == 2) {
[self.moviePlayer play];
}
}
3. 调用系统相册
UIImagePickerController *imagePicker=[[UIImagePickerController alloc]init]; imagePicker.sourceType=UIImagePickerControllerSourceTypePhotoLibrary; // UIImagePickerControllerSourceTypePhotoLibrary,相册 // UIImagePickerControllerSourceTypeCamera,调用相机 // UIImagePickerControllerSourceTypeSavedPhotosAlbum相簿 imagePicker.delegate=self; [self presentViewController:imagePicker animated:YES completion:^{}]; 然后在代理方法中处理图片：
#pragma mark - UIImagePickerControllerDelegate
//照片选择完成回调代理
-(void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info{
}
-(void)imagePickerController:(UIImagePickerController *)picker didFinishPickingImage:(UIImage *)image editingInfo:(NSDictionary *)editingInfo{
UIImageView *view=[[UIImageView alloc]initWithFrame:CGRectMake(0, 0, 100, 100)];
[view setImage:image];
[self.view addSubview:view];
}
基本使用就这些...待完善
～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～
看到黑马做的那个百度音乐播放器，自己照着视频写了一遍，也没有很好的完善，就是熟悉了一下大致思路 Demo地址:
https://github.com/nwgdegitHub/musicPlayDemo
4. 模拟器上进入后台仍能播放音乐，真机上要设置2个地方，一个是Capabilities中Backgroud Modes的第一个开关，另一个是在Appdelegate加点代码：
UIBackgroundTaskIdentifier _bgTaskId; - (void)applicationWillResignActive:(UIApplication *)application { //开启后台处理多媒体事件 [[UIApplication sharedApplication] beginReceivingRemoteControlEvents]; AVAudioSession *session=[AVAudioSession sharedInstance]; [session setActive:YES error:nil]; //后台播放 [session setCategory:AVAudioSessionCategoryPlayback error:nil]; //这样做，可以在按home键进入后台后 ，播放一段时间，几分钟吧。但是不能持续播放网络歌曲，若需要持续播放网络歌曲，还需要申请后台任务id，具体做法是： _bgTaskId = [AppDelegate backgroundPlayerID:_bgTaskId];
}
//实现一下backgroundPlayerID:这个方法:
+(UIBackgroundTaskIdentifier)backgroundPlayerID:(UIBackgroundTaskIdentifier)backTaskId {
//设置并激活音频会话类别
AVAudioSession *session=[AVAudioSession sharedInstance]; [session setCategory:AVAudioSessionCategoryPlayback error:nil]; [session setActive:YES error:nil];
//允许应用程序接收远程控制
[[UIApplication sharedApplication] beginReceivingRemoteControlEvents];
//设置后台任务ID
UIBackgroundTaskIdentifier newTaskId=UIBackgroundTaskInvalid; newTaskId=[[UIApplication sharedApplication] beginBackgroundTaskWithExpirationHandler:nil]; if(newTaskId!=UIBackgroundTaskInvalid&&backTaskId!=UIBackgroundTaskInvalid) { [[UIApplication sharedApplication] endBackgroundTask:backTaskId]; } return newTaskId;
}
这样就能实现进入后台播放了。参考来自 http://www.jianshu.com/p/03d80157948a