項(xiàng)目有個(gè)需求，類似鬧鐘功能，當(dāng)收到后臺(tái)的推送消息后客戶端連續(xù)播放提示語音并讓手機(jī)開啟振動(dòng)，當(dāng)中遇到了不少問題：

1、當(dāng)應(yīng)用一直保持在前臺(tái)的情況下，收到推送消息后語音和振動(dòng)可以正常觸發(fā)
2、在第一條的基礎(chǔ)上，語音和振動(dòng)被觸發(fā)后再按Home鍵進(jìn)入后臺(tái)，這時(shí)語音和振動(dòng)都失效
3、當(dāng)應(yīng)用進(jìn)入后臺(tái)的情況下，收到推送消息后語音和振動(dòng)都不能被觸發(fā)

為解決這一問題，查了大量資料，并驗(yàn)證多遍，可以使用下列兩種方法解決：

一、開啟后臺(tái)持續(xù)定位

1、設(shè)置Backgound Modes

788BFE1C-C1C6-4855-8B44-79878467EB51.png

2、在info.plist中設(shè)置

Privacy - Location Always Usage Description

3 、在didFinishLaunchingWithOptions中執(zhí)行下面的initLocationManager方法

-(void)initLocationManager{
    //1.創(chuàng)建定位管理對(duì)象
    _manager = [[CLLocationManager alloc]init];

    //2.設(shè)置屬性 distanceFilter、desiredAccuracy
    _manager.distanceFilter = kCLDistanceFilterNone;//實(shí)時(shí)更新定位位置
    _manager.desiredAccuracy = kCLLocationAccuracyBest;//定位精確度
    if([_manager respondsToSelector:@selector(requestAlwaysAuthorization)]){
        [_manager requestAlwaysAuthorization];
    }
    //該模式是抵抗程序在后臺(tái)被殺，申明不能夠被暫停
    _manager.pausesLocationUpdatesAutomatically = NO;
    _manager.allowsBackgroundLocationUpdates = YES;
    //3.設(shè)置代理
    _manager.delegate = self;
    //4.開始定位
    [_manager startUpdatingLocation];
    //5.獲取朝向
    [_manager startUpdatingHeading];
}

//定位成功調(diào)用的的方法
-(void)locationManager:(CLLocationManager *)manager didUpdateLocations:(NSArray *)locations{

    // 獲取位置信息
    CLLocation *newLocation=[locations lastObject];
    double lat = newLocation.coordinate.latitude;
    double lon = newLocation.coordinate.longitude;
    double alt = newLocation.altitude;
    NSLog(@"緯度:%f,經(jīng)度:%f,海拔:%f",lat,lon,alt);
}

- (void)applicationWillResignActive:(UIApplication *)application {
    [[UIApplication sharedApplication] beginReceivingRemoteControlEvents];
    
    [self.manager startUpdatingLocation];
}

- (void)applicationDidEnterBackground:(UIApplication *)application {
    
    NSLog(@"進(jìn)入后臺(tái)");
    UIApplication *app = [UIApplication sharedApplication];
    __block  UIBackgroundTaskIdentifier bgTask;
    bgTask = [app beginBackgroundTaskWithExpirationHandler:^{
        dispatch_async(dispatch_get_main_queue(), ^{
            
            if (bgTask != UIBackgroundTaskInvalid){
                bgTask = UIBackgroundTaskInvalid;
            }
        });
    }];
    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
        dispatch_async(dispatch_get_main_queue(), ^{
            if (bgTask != UIBackgroundTaskInvalid){
            bgTask = UIBackgroundTaskInvalid;
            }
        });
    });
    
   [self.manager startUpdatingLocation];
}

二、后臺(tái)連續(xù)播放音樂的方法

1、設(shè)置Backgound Modes

F01AB26A-6E44-4F88-A70A-4CFE4D8A412B.png

2、在didFinishLaunchingWithOptions中執(zhí)行下面的initPlayMusic方法

-(void)initPlayMusic{
  
    //先注冊(cè)響應(yīng)后臺(tái)控制
    [[UIApplication sharedApplication] beginReceivingRemoteControlEvents];
    //處理中斷事件的通知
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(handleInterreption:) name:AVAudioSessionInterruptionNotification object:[AVAudioSession sharedInstance]];
    
    //設(shè)置并激活音頻會(huì)話類別
    AVAudioSession *session = [AVAudioSession sharedInstance];
    [session setCategory:AVAudioSessionCategoryPlayback error:nil];
    [session setActive:YES error:nil];
    
    //播放背景音樂
    NSString *musicPath = [[NSBundle mainBundle] pathForResource:@"紫藤花" ofType:@"mp3"];
    NSURL *url = [[NSURL alloc] initFileURLWithPath:musicPath];
    
    // 創(chuàng)建播放器
    _player = [[AVAudioPlayer alloc] initWithContentsOfURL:url error:nil];
    [_player prepareToPlay];
    _player.volume = 1;
    _player.numberOfLoops = -1; //設(shè)置音樂播放次數(shù)  -1為一直循環(huán)
    [_player play]; //播放
}

//處理中斷事件
-(void)handleInterreption:(NSNotification *)sender{
     NSLog(@"--1->%@",sender.userInfo);
    
    if(_isPlayed){
        [self.player pause];
        _isPlayed = NO;
    }else{
        [self.player play];
        _isPlayed = YES;
    }
}

//應(yīng)用將要進(jìn)入不活躍的狀態(tài)
-(void)applicationWillResignActive:(UIApplication *)application{
    //開啟后臺(tái)處理多媒體事件
    [[UIApplication sharedApplication] beginReceivingRemoteControlEvents];
    AVAudioSession *session=[AVAudioSession sharedInstance];
    [session setActive:YES error:nil];
    //后臺(tái)播放//這樣做，可以在按home鍵進(jìn)入后臺(tái)后 ，播放一段時(shí)間，幾分鐘吧。但是不能持續(xù)播放網(wǎng)絡(luò)歌曲，
    [session setCategory:AVAudioSessionCategoryPlayback error:nil];
    //若需要持續(xù)播放網(wǎng)絡(luò)歌曲，還需要申請(qǐng)后臺(tái)任務(wù)id，具體做法是：
    //其中的_bgTaskId是后臺(tái)任務(wù)UIBackgroundTaskIdentifier _bgTaskId;
    _bgTaskId =[AppDelegate backgroundPlayerID:_bgTaskId];
}

//實(shí)現(xiàn)一下backgroundPlayerID:這個(gè)方法:
+(UIBackgroundTaskIdentifier)backgroundPlayerID:(UIBackgroundTaskIdentifier)backTaskId{
    
    //允許應(yīng)用程序接收遠(yuǎn)程控制
    [[UIApplication sharedApplication] beginReceivingRemoteControlEvents];
    //設(shè)置后臺(tái)任務(wù)ID
    UIBackgroundTaskIdentifier newTaskId = UIBackgroundTaskInvalid;
    newTaskId = [[UIApplication sharedApplication] beginBackgroundTaskWithExpirationHandler:nil];
    if(newTaskId!=UIBackgroundTaskInvalid&&backTaskId!=UIBackgroundTaskInvalid){
        [[UIApplication sharedApplication] endBackgroundTask:backTaskId];
    }
    return newTaskId;
}

以上兩種方法經(jīng)測(cè)試，可以一直在后臺(tái)運(yùn)行不會(huì)被kill掉