iOS实现一个简单的视频播放器

 

说明：用系统自带的AVPlayer类实现一个简单的视频播放器。它既能播放本地视频，也能较流畅地播放网络视频。

首先要引入AVFoundation.framework框架；

播放器类.h文件代码如下：

#import <UIKit/UIKit.h>#import <AVFoundation/AVFoundation.h>@interface PlayView : UIView-(void)setPlayer:(AVPlayer *)myPlayer;-(void)playWith:(NSURL *)url;-(void)releasePlayer;@end

播放器类.m文件代码如下：

#import "PlayView.h"@interface PlayView(){    UIView   *_bgView;    //播放器    AVPlayer *_player;    //用于显示(控制)视频的播放进度    UISlider *_progressSlider;}-(void)uiConfigWith:(CGRect)bframe;@end@implementation PlayView- (id)initWithFrame:(CGRect)frame{    self = [super initWithFrame:frame];    if (self) {        [self uiConfigWith:frame];        [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(moviePlayDidEnd:) name:AVPlayerItemDidPlayToEndTimeNotification object:_player.currentItem];    }    return self;}-(void)uiConfigWith:(CGRect)bframe{    self.backgroundColor=[UIColor blackColor];        _bgView=[[UIView alloc]initWithFrame:CGRectMake(0, bframe.size.height-50, bframe.size.width, 50)];    _bgView.backgroundColor=[UIColor lightGrayColor];    [self addSubview:_bgView];        //播放暂停按钮    UIButton *playBtn = [UIButton buttonWithType:UIButtonTypeCustom];    [playBtn setFrame:CGRectMake(0,0,100,50)];    playBtn.backgroundColor=[UIColor whiteColor];    playBtn.selected=YES;    [playBtn setTitle:@"play" forState:UIControlStateNormal];    [playBtn setTitle:@"pause" forState:UIControlStateSelected];    [playBtn setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];    [playBtn addTarget:self action:@selector(playBtnClick:) forControlEvents:UIControlEventTouchUpInside];    [_bgView addSubview:playBtn];        _progressSlider= [[UISlider alloc] initWithFrame:CGRectMake(100,0,bframe.size.width-100,50)];    _progressSlider.minimumValue = 0.0;    _progressSlider.maximumValue = 1.0;    [_progressSlider addTarget:self action:@selector(progressChange:) forControlEvents:UIControlEventValueChanged];    [_bgView addSubview:_progressSlider];}//每个视图都对应一个层，改变视图的形状、动画效果\与播放器的关联等，都可以在层上操作//播放器支持的播放格式:mp4、mov(iPhone手机录制视频的默认格式) avi-(void)setPlayer:(AVPlayer *)myPlayer{    AVPlayerLayer *playerLayer=(AVPlayerLayer *)self.layer;    [playerLayer setPlayer:myPlayer];}//在调用视图的layer时，会自动触发layerClass方法，重写它，保证返回的类型是AVPlayerLayer+(Class)layerClass{    return [AVPlayerLayer class];}-(void)playWith:(NSURL *)url{    //加载视频资源的类    AVURLAsset *asset = [AVURLAsset assetWithURL:url];    //AVURLAsset 通过tracks关键字会将资源异步加载在程序的一个临时内存缓冲区中    [asset loadValuesAsynchronouslyForKeys:[NSArray arrayWithObject:@"tracks"] completionHandler:^{        //能够得到资源被加载的状态        AVKeyValueStatus status = [asset statusOfValueForKey:@"tracks" error:nil];        //如果资源加载完成,开始进行播放        if (status == AVKeyValueStatusLoaded) {            //将加载好的资源放入AVPlayerItem 中，item中包含视频资源数据,视频资源时长、当前播放的时间点等信息            AVPlayerItem *item = [AVPlayerItem playerItemWithAsset:asset];            _player = [[AVPlayer alloc] initWithPlayerItem:item];            //将播放器与播放视图关联            [self setPlayer:_player];            [_player play];            //需要时时显示播放的进度            //根据播放的帧数、速率，进行时间的异步(在子线程中完成)获取            [_player addPeriodicTimeObserverForInterval:CMTimeMake(1.0, 1.0) queue:dispatch_get_global_queue(0, 0) usingBlock:^(CMTime time) {                //获取时间                //获取当前播放时间(根据帧数和播放速率，视频资源的总长度得到的CMTime)                CMTime current = _player.currentItem.currentTime;                //总时间                CMTime dur =_player.currentItem.duration;                //CMTimeGetSeconds 将描述视频时间的结构体转化为float（秒）                float pro = CMTimeGetSeconds(current)/CMTimeGetSeconds(dur);                //回到主线程刷新UI                dispatch_async(dispatch_get_main_queue(), ^{                    //要考虑到代码的健壮性                    /*1、在向对象发送消息前，要判断对象是否为空                     *2、一些值(数组、控制中的属性值)是否越界的判断                     *3、是否对各种异常情况进行了处理(照片、定位 用户允许、不允许)                     *4、数据存储，对nil的判断或处理                     *5、对硬件功能支持情况的判断等                     */                    if (pro >=0 && pro <=1) {                        _progressSlider.value = pro;                    }                });                            }];        }    }];}#pragma mark -------BtnClick----------(void)playBtnClick:(UIButton *)btn{    if (btn.selected==YES) { //暂停按钮被点击                if (_player) {            [_player pause];        }        btn.selected=NO;        return;    }        //播放按钮被点击    if (_player) {        [_player play];    }    btn.selected=YES;    return;}-(void)progressChange:(UISlider *)sl{    //通过进度条控制播放进度    if (!_player) {        return;    }    CMTime dur = _player.currentItem.duration;    float current = _progressSlider.value;    //CMTimeMultiplyByFloat64 将总时长，当前进度，转化成为CMTime    //seekToTime 跳转到指定的时间    [_player seekToTime:CMTimeMultiplyByFloat64(dur, current)];}//销毁player-(void)releasePlayer{    if (_player) {        [_player pause];        _player=nil;    }    [[NSNotificationCenter defaultCenter] removeObserver:self];    for(int i=0;i<[_bgView.subviews count];i++)    {        UIView *view=[_bgView.subviews objectAtIndex:i];        [view removeFromSuperview];        view=nil;        i--;    }    [_bgView removeFromSuperview];    _bgView=nil;}#pragma mark ------Notification--------(void)moviePlayDidEnd:(NSNotification*)notification{    NSLog(@"视频播放完毕！");}@end

这个简单的视频播放器类就做好了。

在ViewController类中创建一个简单的按钮，点击按钮，调用PlayView类播放视频。

如果是网络视频，

NSURL *url = [NSURL URLWithString:@"http://123.com/123.mp4"];

如果是本地视频，

NSString *path=[[NSBundle mainBundle]pathForResource:@"123.mp4" ofType:nil];NSURL *url=[NSURL fileURLWithPath:path];

调用：

PlayView *playView=[[PlayView alloc] initWithFrame:CGRectMake(0, 0, 320, 300)];[playView playWith:url];[self.view addSubview:playView];

这样，视频就可以播放了！