9.28. IOS accelerometer (accelerometer)

发布时间 : 2025-10-25 13:32:32 UTC      

Page Views: 10 views

9.28.1. Brief introduction

The accelerometer detects the change in the position of the device according to the x, y and z directions.

The position of the current equipment relative to the ground can be known through the accelerometer.

The following example code needs to run on a real device and does not work on the simulator.

9.28.2. Instance step

1、创建一个简单的视图应用程序

2、在ViewController.xib中添加三个标签,并创建一个ibOutlets分别为:xlable、ylabel和zlabel

3、如下所示,更新ViewController.h

#import 

@interface ViewController : UIViewController<UIAccelerometerDelegate>
{
    IBOutlet UILabel *xlabel;
    IBOutlet UILabel *ylabel;
    IBOutlet UILabel *zlabel;

}
@end
   

4、如下所示,更新ViewController.m

#import "ViewController.h"

@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad
{
    [super viewDidLoad];
    [[UIAccelerometer sharedAccelerometer]setDelegate:self];
    //Do any additional setup after loading the view,typically from a nib
}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}
- (void)accelerometer:(UIAccelerometer *)accelerometer didAccelerate:
  (UIAcceleration *)acceleration{
    [xlabel setText:[NSString stringWithFormat:@"%f",acceleration.x]];
    [ylabel setText:[NSString stringWithFormat:@"%f",acceleration.y]];
    [zlabel setText:[NSString stringWithFormat:@"%f",acceleration.z]];
}

@end

9.28.3. Output

When we run the application on the iPhone device, the output is shown below.

accelerometer_Output

《地理信息系统原理、技术与方法》  97

最近几年来,地理信息系统无论是在理论上还是应用上都处在一个飞速发展的阶段。 GIS被应用于多个领域的建模和决策支持,如城市管理、区划、环境整治等等,地理信息成为信息时代重要的组成部分之一; “数字地球”概念的提出,更进一步推动了作为其技术支撑的GIS的发展。 与此同时,一些学者致力于相关的理论研究,如空间感知、空间数据误差、空间关系的形式化等等。 这恰好说明了地理信息系统作为应用技术和学科的两个方面,并且这两个方面构成了相互促进的发展过程。