5

我正在尝试使用 rhomobile 框架让 iphone 的指南针工作。我已经完成了 rhomobile 部分，创建了一个在 iphone 上调用本机方法的工作包装器，但我无法让事件正常工作。

位置管理器.h

#import <UIKit/UIKit.h>
#import <CoreLocation/CoreLocation.h>

@interface locationController : NSObject <CLLocationManagerDelegate> 
{
    CLLocationManager *locationManager;
}
@property (strong, nonatomic) CLLocationManager *locationManager;

- (id)init;
- (void)dealloc;

@end

位置管理器.m

#import "Locationmanager.h"

#include "ruby/ext/rho/rhoruby.h"

//store the values
double gx, gy, gz, gth;

//init location
locationController *lc;
@implementation locationController

@synthesize locationManager;

- (id)init {
if (self = [super init]) {
    self.locationManager = [[CLLocationManager alloc] init];

    NSLog(@"%@", [CLLocationManager headingAvailable]? @"\n\nHeading available!\n" : @"\n\nNo heading..\n");
    NSLog(@"%@", [CLLocationManager locationServicesEnabled]? @"\n\nLocation available!\n" : @"\n\nNo location..\n");

    // check if the hardware has a compass
    if ([CLLocationManager headingAvailable] == NO) {
        // No compass is available. This application cannot function without a compass, 
        // so a dialog will be displayed and no magnetic data will be measured.
        locationManager = nil;
        UIAlertView *noCompassAlert = [[UIAlertView alloc] initWithTitle:@"No Compass!" message:@"This device does not have the ability to measure magnetic fields." delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil];
        [noCompassAlert show];
        [noCompassAlert release];
        NSLog(@"\n***** ERROR *****\n No compass found !!!");
    } else {
        // setup delegate callbacks
        locationManager.delegate = self;

        // heading service configuration
        locationManager.headingFilter = kCLHeadingFilterNone;

        // location service configuration
        locationManager.distanceFilter = kCLDistanceFilterNone;
        locationManager.desiredAccuracy = kCLLocationAccuracyNearestTenMeters;

        //start location services
        [locationManager startUpdatingLocation];

        // start the compass
        [locationManager startUpdatingHeading];

    }
return self;
}
}
- (void)dealloc {    
    [super dealloc];
    // Stop the compass
    [locationManager stopUpdatingHeading];
    [locationManager release];
}

// This delegate method is invoked when the location manager has heading data.
- (void)locationManager:(CLLocationManager *)manager didUpdateHeading:(CLHeading *)heading {
    NSLog(@"\n\n***** New magnetic heading *****\n %f\n", heading.magneticHeading);
    NSLog(@"\n\n***** New true heading *****\n %f\n", heading.trueHeading);
    gx = heading.x;
    gy = heading.y;
    gz = heading.z;
    gth = heading.trueHeading;
}

// This delegate method is invoked when the location managed encounters an error condition.
- (void)locationManager:(CLLocationManager *)manager didFailWithError:(NSError *)error {
    if ([error code] == kCLErrorDenied) {
        // This error indicates that the user has denied the application's request to use location services.
        NSLog(@"\n ***** ERROR *****\n Location not allowed!");
        [locationManager stopUpdatingHeading];
    } else if ([error code] == kCLErrorHeadingFailure) {
        NSLog(@"\n ***** ERROR *****\n Magnetic interference or something!");
    }
}

@end

//ruby wrappers
void locationmanager_init(void) {
   // make sure we can only start this method once
   static bool started = false;
   if(!started) {
       // Initialize the Objective C accelerometer class.
       lc = [[locationController alloc] init];
       started = true;
   }

}

void locationmanager_get_heading(double *x, double *y, double *z, double *th) {
    NSLog(@"\n ***** DEBUGGER *****\n Getting heading  x: %f, y: %f, z: %f, heading: %f", gx, gy, gz, gth);
    *x = gx;
    *y = gy;
    *z = gz;
    *th = gth;
}

我在带有 iOS 5.1 的 iphone 4 上运行代码，在控制台中我可以看到 init 的调试消息，但我从未看到 didUpdateHeading 委托的调试消息。有人知道我在这里错过了什么吗？

更新

我想我需要在后台线程中运行我的代码才能让它工作。当前 locationmanager_init 初始化 + 离开代码，因此它不活动并且不会触发事件。任何人都有一个简单的解决方案在后台初始化它以使其保持活动状态？

更新 2

已返回 id，已使用self = [super init]但仍未修复 :(

GitHub 代码 使用 locationmanager_init 初始化，使用 locationmanager_get_heading 检索数据

4

3 回答 3

14

您必须CLLocationManager在主线程上初始化，在此处检查此 SO ，或从具有活动运行循环的线程运行它，在此处检查此 SO ，来自 Apple 文档：

Configuration of your location manager object must always occur on a thread with 
an active run loop, such as your application’s main thread.

确保你locationController和CCLocationManager它的内部在初始化之后仍然存在，检查这里。我在这里可能错了，但是从您的 Github 代码来看，该*lc变量似乎正在自动释放池中释放。尝试给它额外的保留。

lc = [[[locationController alloc] init] retain];

我想这是你问题的原因。如果对象被释放，您将不会获得任何更新。

与问题无关，但：

你应该最后而不是第一个打电话，在这里[super dealloc]检查这个

将 return 语句放在 init 方法中最后一个括号之前，而不是在倒数第二个之前。

        ...
        // start the compass
        [locationManager startUpdatingHeading];

        }
    }
    return self;
}
于 2012-09-12T19:43:49.000 回答
0 
- (void)locationManager:(CLLocationManager *)manager 
didUpdateHeading:(CLHeading *)heading;
- (void)locationManager:(CLLocationManager *)manager 
didFailWithError:(NSError *)error;

这些是您的实例方法而不是委托方法。

检查 https://developer.apple.com/library/mac/#documentation/CoreLocation/Reference/CLLocationManagerDelegate_Protocol/CLLocationManagerDelegate/CLLocationManagerDelegate.html

于 2012-08-31T15:27:07.757 回答
0

可能这不是整体问题的解决方案，但您的init方法缺少返回语句：

- (id)init {
  if (self = [super init]) {
    // do your setup here
  }

  return self;
}
于 2012-09-10T09:24:42.020 回答