iOS开发气压计

#import 

 //设备是否支持气压计

    NSLog(@"%d",[CMAltimeter isRelativeAltitudeAvailable]);

    

    //启用气压计

    self.altimeter = [[CMAltimeter alloc]init];

    [self.altimeter startRelativeAltitudeUpdatesToQueue:NSOperationQueue.mainQueue withHandler:^(CMAltitudeData * _Nullable altitudeData, NSError * _Nullable error) {

        NSLog(@"%lf",[altitudeData.relativeAltitude floatValue]);

        NSLog(@"%@",error);

    }];