iOS 获取手机电量 电量变化通知

#pragma mark - 电池电量获取及监控
-(void)checkAndMonitorBatteryLevel{
    
    //拿到当前设备
    UIDevice * device = [UIDevice currentDevice];
    
    //是否允许监测电池
    //要想获取电池电量信息和监控电池电量 必须允许
    device.batteryMonitoringEnabled = true;
    
    //1、check
    /*
     获取电池电量
     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];
    
}

// 电量变化 
- (void)didChangeBatteryLevel:(id)sender{
    //电池电量发生改变时调用
    UIDevice *myDevice = [UIDevice currentDevice];
    [myDevice setBatteryMonitoringEnabled:YES];
    float batteryLevel = [myDevice batteryLevel];
    NSLog(@"电池剩余比例：%@", [NSString stringWithFormat:@"%f",batteryLevel*100]);
}