iphone - 在 iphone 中查找方向，例如 North 等

Question

我的应用程序有一个问题，我想知道从当前纬度和经度到纬度和经度的方向

-(void)showDirection
{
 CGFloat latitude = Lat;
 if (latitude < 0) {
    latitude = -latitude;
    strDirection = @"S";
 } else {
    strDirection = @"N";
 }
 // Longitude
 CGFloat longitude = Long;
 if (longitude < 0) {
    longitude = -longitude;
    strDirection = @"W";
 } else {
    strDirection = @"E";
 }
 NSLog(@"direc %@",strDirection);
}

Answer 1

试试下面的代码:

首先在你的项目中添加框架CoreLocation.Framework，然后添加初始化CLLocationManager对象并导入CLLocationManager头文件。

你的viewcontroller.h

#import <CoreLocation/CoreLocation.h>
@interface Yourviewcontroller :UIViewController <CLLocationManagerDelegate>
{
      CLLocationManager *locationManager;
} 

你的viewcontroller.m

locationManager=[[CLLocationManager alloc] init];
locationManager.desiredAccuracy = kCLLocationAccuracyBest;
locationManager.delegate = self;
//Start the compass updates.
[locationManager startUpdatingHeading];

添加获取当前方向的函数

-(void)locationManager:(CLLocationManager *)manager didUpdateHeading:(CLHeading *)newHeading
{
    float mHeading = newHeading.magneticHeading;
    if ((mHeading >= 339) || (mHeading <= 22)) {
        //[direction setText:@"N"]; 

    }else if ((mHeading > 23) && (mHeading <= 68)) {
        //[direction setText:@"NE"];    

    }else if ((mHeading > 69) && (mHeading <= 113)) {
        //[direction setText:@"E"]; 

    }else if ((mHeading > 114) && (mHeading <= 158)) {
        //[direction setText:@"SE"];

    }else if ((mHeading > 159) && (mHeading <= 203)) {
        //[direction setText:@"S"]; 

    }else if ((mHeading > 204) && (mHeading <= 248)) {
        //[direction setText:@"SW"];    

    }else if ((mHeading > 249) && (mHeading <= 293)) {
       // [direction setText:@"W"];

    }else if ((mHeading > 294) && (mHeading <= 338)) {
       // [direction setText:@"NW"];

     }
}

注意:指南针只能在真实的 iPhone 设备上使用，不能在 iPhone 模拟器中使用..!