当iPhone被锁定时，AVAudioPlayer无法在后台播放 [英] AVAudioPlayer is not playing in Background when iPhone is locked

问题描述

实际上我从文档目录中获取歌曲。

Actually i fetching the songs from Documents Directory.

我推荐此链接： - http://www.raywenderlich.com/29948/backgrounding-for-ios ，但它只播放来自捆绑的歌曲。但我想播放文件目录中的歌曲。

I referred this Link:- http://www.raywenderlich.com/29948/backgrounding-for-ios , But it will play the songs from bundle only. but i want to play the songs from documents Directory.

我试过

1. Plist中的背景模式

1. Background modes in the Plist

应用程序不在背景中=在Plist中没有

Application Does not in background = No in Plist

在Appdelegate中didFinishLaunchingWithOptions： -

In Appdelegate didFinishLaunchingWithOptions:-

NSError *setCategoryErr = nil;
NSError *activationErr  = nil;
[[AVAudioSession sharedInstance] setCategory: AVAudioSessionCategoryPlayback error:&setCategoryErr];
[[AVAudioSession sharedInstance] setActive:YES error:&activationErr];

PlayMethod（）

PlayMethod()

{
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);

NSString *documentsDirectory = [paths objectAtIndex:0];

NSString *path = [documentsDirectory stringByAppendingPathComponent:saveFileName];

NSURL *url1 = [[NSURL alloc] initFileURLWithPath: path];

self.audioPlayer=[[AVAudioPlayer alloc] initWithContentsOfURL:url1 error:NULL];

[self.audioPlayer play];
self.seekBarSlider.minimumValue = 0.0f;
self.seekBarSlider.maximumValue = self.audioPlayer.duration;
//[self updateTime];

self.isPlaying=YES;

[[AVAudioSession sharedInstance] setCategory:AVAudioSessionCategoryPlayback error:nil];
[[AVAudioSession sharedInstance] setActive: YES error: nil];

_audioPlayer.delegate=self;

NSError *error;

UIBackgroundTaskIdentifier bgTaskId = 0;

if (_audioPlayer == nil)
    NSLog([error description]);
else{


    UIBackgroundTaskIdentifier newTaskId = UIBackgroundTaskInvalid;

    [_audioPlayer prepareToPlay];

    if([_audioPlayer play]){

        newTaskId = [[UIApplication sharedApplication] beginBackgroundTaskWithExpirationHandler:NULL];

    }

    if (newTaskId != UIBackgroundTaskInvalid && bgTaskId != UIBackgroundTaskInvalid)
        [[UIApplication sharedApplication] endBackgroundTask: bgTaskId];

    bgTaskId = newTaskId;
}

}

数据保护：

DATA PROTECTION:

 Under the Xcode -> capabilities .

所有我尝试但不工作！任何人都可以帮助我。

All I tried But not working!. Can anyone help me.

推荐答案

我使用了数据保护机制，特别是之前我打算将NSDATA写入Documents目录。我需要将Protection None设置为特定的文件路径。所以我使用 NSProtectionNone 属性作为文件路径。 如果我们不设置ProtentionNone属性，Apple将不允许访问锁定状态下的文件。

I used Data Protection mechanism and particularly before I am going to write the NSDATA into Documents directory. I need to set the Protection None to particular file path. So I used NSProtectionNone Property for the file path. If we won't set the ProtentionNone property the Apple won't allow to access the file on Locked State.

NSDictionary *protection = [NSDictionary dictionaryWithObject:NSFileProtectionNone forKey:NSFileProtectionKey];
[[NSFileManager defaultManager] setAttributes:protection ofItemAtPath:_path error:nil];   

if( [_rawData writeToFile:_path atomically:YES])
{
    NSLog(@"HOpefully written into Documentz directory..");

}
else
{
    NSLog(@"Writting file mechanism - Failed!");
}

我曾经从App Bundle以无限循环播放Dummy音频文件。因此使用AVFoundation Framework连续播放虚拟音频文件。所以我可以连续访问Documents目录音频文件。一个接一个。

And I used to play the Dummy audio file in infinite loop from App Bundle. so the dummy audio file is playing continuously using AVFoundation Framework. So I can able to access the Documents directory audio files continuously. one by one.

这篇关于当iPhone被锁定时，AVAudioPlayer无法在后台播放的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！