iOS：APP后台永久保活方法

Signing&Capabilites开启Audio，AirPlay，and Picture in Picture模式

应用在后台时播放声音信息，可以利用此模式播放无声音频，APP进入后台播放无声音频，可以实现APP长时间保活

代码如下

编写音乐播放类

#import <Foundation/Foundation.h>

#import<AVFoundation/AVFoundation.h>

@interface BackgroundPlayer : NSObject<AVAudioPlayerDelegate>

@property(nonatomic,strong)AVAudioPlayer* player;

- (void)startPlayer;

- (void)stopPlayer;

@end

#import "BackgroundPlayer.h"

@implementation BackgroundPlayer

- (void)startPlayer

{

    if(_player&& [_playerisPlaying]) {

        return;

    }

    AVAudioSession *session = [AVAudioSession sharedInstance];

    [[AVAudioSession sharedInstance] setMode:AVAudioSessionModeDefault error:nil];

    NSString* route = [[[[[AVAudioSession sharedInstance] currentRoute] outputs] objectAtIndex:0] portType];

    if ([route isEqualToString:AVAudioSessionPortHeadphones] || [route isEqualToString:AVAudioSessionPortBluetoothA2DP] || [route isEqualToString:AVAudioSessionPortBluetoothLE] || [route isEqualToString:AVAudioSessionPortBluetoothHFP]) {

        if(@available(iOS10.0, *)) {

            [[AVAudioSession sharedInstance] setCategory:AVAudioSessionCategoryPlayAndRecord

                                             withOptions:(AVAudioSessionCategoryOptionMixWithOthers | AVAudioSessionCategoryOptionAllowBluetooth | AVAudioSessionCategoryOptionAllowBluetoothA2DP)

                                                   error:nil];

        }else{

            // Fallback on earlier versions

        }

    }else{

        [[AVAudioSession sharedInstance] setCategory:AVAudioSessionCategoryPlayAndRecord

                                         withOptions:(AVAudioSessionCategoryOptionMixWithOthers | AVAudioSessionCategoryOptionDefaultToSpeaker)

                                               error:nil];

    }

    [session setActive:YESerror:nil];

    NSString *filePath = [[NSBundle mainBundle] pathForResource:@"payment" ofType:@"mp3"];

    NSURL*fileURL = [[NSURLalloc]initFileURLWithPath:filePath];

    if(!fileURL) {

        NSLog(@"找不到播放文件");

    }

    _player = [[AVAudioPlayer alloc] initWithContentsOfURL:fileURL error:nil];

    [_player prepareToPlay];

    [_player setDelegate:self];

    _player.volume=0.0;

    _player.numberOfLoops = -1;

    BOOLret = [_playerplay];

    if(!ret) {

        NSLog(@"播放失败play failed,please turn on audio background mode");

    }

}

- (void)stopPlayer

{

    if(_player) {

        [_playerstop];

        _player=nil;

        AVAudioSession *session = [AVAudioSession sharedInstance];

        [session setActive:NOerror:nil];

        NSLog(@"播放暂停stop in play background success");

    }

}

@end

在AppDelegate.m中添加监听

UIApplicationWillEnterForegroundNotification（应用进入前台通知）UIApplicationDidEnterBackgroundNotification（应用进入后台通知）

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(appWillEnterForeground) name:UIApplicationWillEnterForegroundNotification object:nil];

    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(appDidEnterBackground) name:UIApplicationDidEnterBackgroundNotification object:nil];

@property(nonatomic,strong)BackgroundPlayer*player;

-(void)appWillEnterForeground{

if(self.player){

[self.player stopPlayBackgroundAlive];

}

}

-(void)appDidEnterBackground{

if(_player==nil){

_player=[[BackgroundPlayer alloc]init];

}

[self.player startPlayer];

}