IOS实现基于CMPedometer的计步器

#import "ViewController.h" #import <CoreMotion/CoreMotion.h>  @interface ViewController ()  @property (weak, nonatomic) IBOutlet UILabel *stepLabel; @property(nonatomic,strong) CMPedometer *stepter; @property (weak, nonatomic) IBOutlet UILabel *totalLabel;  @end  @implementation ViewController  - (void)viewDidLoad {   [super viewDidLoad];      if(![CMPedometer isStepCountingAvailable])   {     NSLog(@"计步器不可用");     return;   }      _stepter =[[CMPedometer alloc]init];      NSTimeInterval secondsPerDay =24*60*60;   NSDate *date =[NSDate date];   NSDate *yesterDay =[date dateByAddingTimeInterval:-secondsPerDay];         [_stepter startPedometerUpdatesFromDate:yesterDay withHandler:^(CMPedometerData * _Nullable pedometerData, NSError * _Nullable error) {               if(error)     {       NSLog(@"error ==%@",error);     }else     {       NSNumber *steps =pedometerData.numberOfSteps;       NSNumber *distance =pedometerData.distance;              NSDictionary *dic =@{                  @"steps":steps,                  @"distance":distance                  };              NSLog(@"过去一天你一共走了%@步,一共%@米",steps,distance);              [self performSelectorOnMainThread:@selector(refreshUI:) withObject:dic waitUntilDone:NO];            }    }];    }  -(void)refreshUI:(NSDictionary *)dic {   NSNumber *distance =dic[@"distance"];   float meters =[distance floatValue];      self.stepLabel.text =[NSString stringWithFormat:@"%@",dic[@"steps"]];   self.totalLabel.text =[NSString stringWithFormat:@"%.2f",meters]; }  - (void)didReceiveMemoryWarning {   [super didReceiveMemoryWarning];   // Dispose of any resources that can be recreated. }   @end