媒體播放器(AVAudioPlayer,MPMoviePlayerViewController)

標籤：avaudioplayer   mpmovieplayerviewcon   nsnotificationcenter   音樂播放器   媒體播放   

概要

       本章主要接到上次的文章講音頻播放，因為音頻播放沒有對應的播放視圖控制項，所以本例子自繪了一個簡單的音樂播放介面，包括返回、暫停/播放、進度控制等。

結果展示

（暫停/播放 播放進度拖拉 返回）

流程概要

1.接上次的流程建立一個音樂播放類，類比MPMoviePlayerViewController的實現；

2.播放音訊時使用IOS內建的類AVAudioPlayer，該類支援播放wav.mp3等格式的音樂，其對應的代理類為AVAudioPlayerDelegate；

3.對於這種初始化賦值代碼：self._buttonPlayPause = [[UIButton alloc] init]；突然想到這種賦值會存在記憶體泄露 ，因為分配記憶體直接賦值給屬性變數，變數retain兩次最後卻只release一次。所以以前的好多代碼都有問題。汗！！！

4.NSNotificationCenter添加監視時注意object不要為空白而要設為nil，不能會導致難發現的記憶體奔潰問題。

主要代碼h檔案

////  MusicPlayerViewController.h//  MediaPlayer////  Created by God Lin on 14/12/15.//  Copyright (c) 2014年 arbboter. All rights reserved.//#import <UIKit/UIKit.h>#import <AVFoundation/AVFoundation.h>@interface MusicPlayerViewController : UIViewController <AVAudioPlayerDelegate>{    AVAudioPlayer* _audioPlayer;    UIButton* _buttonPlayPause;    UIButton* _buttonReturn;    UIImage* _imagePause;    UIImage* _imagePlay;    UIImage* _imageReturn;    UISlider* _sliderPlayer;    NSURL* _urlMusic;    NSTimer* _timerPlayProcess;    BOOL _bPlay;        UITextView* _textViewInfo;    NSString* _titleMusic;}@property (nonatomic, retain) AVAudioPlayer* _audioPlayer;@property (nonatomic, retain) UIButton* _buttonPlayPause;@property (nonatomic, retain) UIButton* _buttonReturn;@property (nonatomic, retain) UISlider* _sliderPlayer;@property (nonatomic, retain) NSURL* _urlMusic;@property (nonatomic, retain) UIImage* _imagePause;@property (nonatomic, retain) UIImage* _imagePlay;@property (nonatomic, retain) UIImage* _imageReturn;@property (nonatomic, readwrite) BOOL _bPlay;@property (nonatomic, retain) NSTimer* _timerPlayProcess;@property (nonatomic, retain) UITextView* _textViewInfo;@property (nonatomic, retain) NSString* _titleMusic;-(id)initWithContentURL:(NSURL*)url;-(void)setContentURL:(NSURL*)url;@endvoid AudioFinishedCallBack(SystemSoundID idSound, void* data);                        

m檔案

////  MusicPlayerViewController.m//  MediaPlayer////  Created by God Lin on 14/12/15.//  Copyright (c) 2014年 arbboter. All rights reserved.//#import "MusicPlayerViewController.h"@interface MusicPlayerViewController ()@end@implementation MusicPlayerViewController@synthesize _audioPlayer, _urlMusic;@synthesize _buttonPlayPause, _buttonReturn;@synthesize _sliderPlayer, _titleMusic;@synthesize _imagePause, _imageReturn, _imagePlay;@synthesize _bPlay, _timerPlayProcess, _textViewInfo;// 布局-(void) doRotateAction:(NSNotification *) notification{    [self relayout];}-(void)relayout{    CGFloat x = self.view.frame.origin.x;    CGFloat y = self.view.frame.origin.y + 20;    CGFloat w = self.view.frame.size.width;    CGFloat h = self.view.frame.size.height - 20;        CGFloat x1 = 0;    CGFloat y1 = 0;    CGFloat w1 = 0;    CGFloat h1 = 0;    UIImage* image = self._imagePause;        if(w < h)    {        image = [UIImage imageNamed:@"oca.jpeg"];    }    else    {        image = [UIImage imageNamed:@"flower.jpg"];    }    self.view.backgroundColor = [UIColor colorWithPatternImage:image];        image = self._imageReturn;    x1 = x + 5;    y1 = y + 5;    w1 = image.size.width;    h1 = image.size.height;    self._buttonReturn.frame = CGRectMake(x1, y1, w1, h1);        image = self._imagePause;    x1 = x + 5;    y1 = (y + h) - (image.size.height + 5);    w1 = image.size.width;    h1 = image.size.height;    self._buttonPlayPause.frame = CGRectMake(x1, y1, w1, h1);        x1 += image.size.width ;    w1 = x + w - 5 - x1;    self._sliderPlayer.frame = CGRectMake(x1, y1, w1, h1);        x1 = x + 5;    y1 = y + h/4;    w1 = w - 10;    h1 = h/2;    NSArray* fontArray = [UIFont familyNames];    NSString* fontName = [fontArray objectAtIndex:arc4random()%[fontArray count]];    _textViewInfo.font = [UIFont fontWithName:fontName size:h1/10];    _textViewInfo.frame = CGRectMake(x1, y1, w1, h1);    _textViewInfo.editable = NO;    _textViewInfo.textAlignment = NSTextAlignmentCenter;    _textViewInfo.backgroundColor = [UIColor clearColor];}// 播放介面控制項-(void)onDragPlayProcess{    [self._audioPlayer setCurrentTime:self._sliderPlayer.value];}-(void)onPlayProcess{    self._sliderPlayer.value = self._audioPlayer.currentTime;        NSInteger nTime = _sliderPlayer.value;    NSInteger nMaxTime = _sliderPlayer.maximumValue;    NSString* info = [[NSString alloc] initWithFormat:@"%@\n%02ld:%02ld - %02ld:%02ld", _titleMusic, nTime/60, nTime%60, nMaxTime/60, nMaxTime%60];    _textViewInfo.text = info;    [info release];}// 設定播放的檔案-(id)initWithContentURL:(NSURL*)url{    self = [super init];    if(self)    {        [self setContentURL:url];    }    return self;}-(void)setContentURL:(NSURL*)url{    self._urlMusic = url;}// 啟動播放，畫面出現前-(void)viewWillAppear:(BOOL)animated{    [self onPlay];}- (void)viewDidLoad{    [super viewDidLoad];        self._imagePlay = [UIImage imageNamed:@"play.png"];    self._imagePause = [UIImage imageNamed:@"pause.png"];    self._imageReturn = [UIImage imageNamed:@"return.png"];        // 突然想到這種賦值會存在記憶體泄露 -> 分配記憶體直接賦值給屬性變數    // 因為retain兩次最後卻只release一次，所以以前的好多都有問題    // 汗！！！    UIButton* button = nil;    button = [[UIButton alloc] init];    self._buttonPlayPause = button;    [button release];    [self.view addSubview:self._buttonPlayPause];    [self._buttonPlayPause setImage:self._imagePause forState:UIControlStateNormal];    [self._buttonPlayPause addTarget:self action:@selector(onPlayPause) forControlEvents:UIControlEventTouchUpInside];        button = [[UIButton alloc] init];     self._buttonReturn = button;    [button release];    [self.view addSubview:self._buttonReturn];    [self._buttonReturn setImage:self._imageReturn forState:UIControlStateNormal];    [self._buttonReturn addTarget:self action:@selector(onStop) forControlEvents:UIControlEventTouchUpInside];        UISlider* slider = [[UISlider alloc] init];    self._sliderPlayer = slider;    [slider release];    [self.view addSubview:self._sliderPlayer];    [self._sliderPlayer addTarget:self action:@selector(onDragPlayProcess) forControlEvents:UIControlEventValueChanged];        UITextView* textView = [[UITextView alloc] init];    self._textViewInfo = textView;    [textView release];    [self.view addSubview:_textViewInfo];        [self relayout];        // 切屏    [[NSNotificationCenter defaultCenter] addObserver:self                                             selector:@selector(doRotateAction:)                                                 name:UIDeviceOrientationDidChangeNotification                                               object:self];}-(void)onPlay{    if(!_bPlay)    {        NSError* error;        self._bPlay = YES;        AVAudioPlayer* player = [[AVAudioPlayer alloc] initWithContentsOfURL:self._urlMusic error:&error];        self._audioPlayer = player;        [player release];        self._audioPlayer.delegate = self;                self._timerPlayProcess = [NSTimer scheduledTimerWithTimeInterval:1 target:self selector:@selector(onPlayProcess) userInfo:nil repeats:YES];                        //self._audioPlayer;        self._sliderPlayer.maximumValue = 0.0f;        // 設定播放時間長度        self._sliderPlayer.maximumValue = self._audioPlayer.duration;        [self._audioPlayer play];                // 非法音頻        if(_sliderPlayer.maximumValue == 0)        {            [self onStop];        }                [self onPlayProcess];    }}-(void)onStop{    [self dismissViewControllerAnimated:YES completion:nil];    [self._audioPlayer stop];    [self._timerPlayProcess invalidate];    _bPlay = NO;}-(void)onPlayPause{    UIImage* image = nil;    _bPlay = !_bPlay;    if(_bPlay)    {        image = self._imagePause;        [self._audioPlayer play];    }    else    {        image = self._imagePlay;        [self._audioPlayer pause];    }    [self._buttonPlayPause setImage:image forState:UIControlStateNormal];}- (void)didReceiveMemoryWarning{    [super didReceiveMemoryWarning];    // Dispose of any resources that can be recreated.}-(void)dealloc{    [_buttonReturn release];    [_buttonPlayPause release];    [_imageReturn release];    [_imagePause release];    [_imagePlay release];    [_audioPlayer release];    [_urlMusic release];    [_sliderPlayer release];    [[NSNotificationCenter defaultCenter] removeObserver:self];    [super dealloc];}#pragma mark - AVAudioPlayerDelegate- (void)audioPlayerDidFinishPlaying:(AVAudioPlayer *)player successfully:(BOOL)flag{    NSLog(@"Music play over");    [self onStop];}/* if an error occurs while decoding it will be reported to the delegate. */- (void)audioPlayerDecodeErrorDidOccur:(AVAudioPlayer *)player error:(NSError *)error{    NSLog(@"Music play occured error");    [self onStop];}@end// 音頻播放回呼函數void AudioFinishedCallBack(SystemSoundID idSound, void* data){    AudioServicesDisposeSystemSoundID(idSound);}

項目工程

媒體播放器(AVAudioPlayer,MPMoviePlayerViewController)