#pragma mark - 電池電量獲取及監(jiān)控
-(void)checkAndMonitorBatteryLevel{
    
    //拿到當(dāng)前設(shè)備
    UIDevice * device = [UIDevice currentDevice];
    
    //是否允許監(jiān)測電池
    //要想獲取電池電量信息和監(jiān)控電池電量 必須允許
    device.batteryMonitoringEnabled = true;
    
    //1、check
    /*
     獲取電池電量
     0 .. 1.0. -1.0 if UIDeviceBatteryStateUnknown
     */
    float level = device.batteryLevel;
    NSLog(@"level = %lf",level);
    
    //2、monitor
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(didChangeBatteryLevel:) name:@"UIDeviceBatteryLevelDidChangeNotification" object:device];
    
}

// 電量變化 
- (void)didChangeBatteryLevel:(id)sender{
    //電池電量發(fā)生改變時調(diào)用
    UIDevice *myDevice = [UIDevice currentDevice];
    [myDevice setBatteryMonitoringEnabled:YES];
    float batteryLevel = [myDevice batteryLevel];
    NSLog(@"電池剩余比例：%@", [NSString stringWithFormat:@"%f",batteryLevel*100]);
}