iO（CoreLocation）-locationManager：didUpdateLocations：无法正常工作 [英] iOs (CoreLocation) - locationManager:didUpdateLocations: not working as expected
问题描述
我写了一个简单的iPhone应用程序，用于检索位置信息并简单地显示它们。
每当位置更改时，我都要增加 distanceTraveled 变量。
我的问题是在方法 locationManager：（CLLocationManager *）manager didUpdateLocations：（NSArray *）locations ， locations.count 始终等于1。我以为每次调用该方法时都会在数组中添加一个元素，但似乎不是这样...
I wrote a simple iPhone app that retrieves location information and simply display them.
I want to increment the distanceTraveled variable every time the position changes.
My problem is that in the method locationManager:(CLLocationManager *)manager didUpdateLocations:(NSArray *)locations, locations.count is always equal to one. I thought it would add an element to the array every time the method is called, but it seems not like that...
我正在模拟器中运行应用程序（我现在没有设备）。
I am running the application in the simulator (I don't have a device now).
这是我的代码：
// BIDViewController.h
#import <UIKit/UIKit.h>
#import <CoreLocation/CoreLocation.h>
@interface BIDViewController : UIViewController <CLLocationManagerDelegate>
@property (strong, nonatomic) CLLocationManager *locationManager;
@property (strong, nonatomic) CLLocation *startingPoint;
@property (strong, nonatomic) IBOutlet UILabel *latitudeLabel;
@property (strong, nonatomic) IBOutlet UILabel *longitudeLabel;
@property (strong, nonatomic) IBOutlet UILabel *horizontalAccuracyLabel;
@property (strong, nonatomic) IBOutlet UILabel *altitudeLabel;
@property (strong, nonatomic) IBOutlet UILabel *verticalAccuracyLabel;
@property (strong, nonatomic) IBOutlet UILabel *distanceTraveledLabel;
@end
// BIDViewController.m :
#import "BIDViewController.h"
@interface BIDViewController ()
@property (strong, nonatomic)CLLocation *currentLocation;
@property (strong, nonatomic)CLLocation *lastLocation;
@property CLLocationDistance distanceTraveled;
@end
@implementation BIDViewController
@synthesize latitudeLabel;
@synthesize locationManager;
@synthesize longitudeLabel;
@synthesize startingPoint;
@synthesize altitudeLabel;
@synthesize distanceTraveledLabel;
@synthesize horizontalAccuracyLabel;
@synthesize verticalAccuracyLabel;
@synthesize currentLocation;
@synthesize lastLocation;
@synthesize distanceTraveled;
- (void)viewDidLoad
{
[super viewDidLoad];
locationManager = [[CLLocationManager alloc] init];
locationManager.delegate = self;
locationManager.desiredAccuracy = kCLLocationAccuracyBest;
//locationManager.distanceFilter = 10.0f;
[locationManager startUpdatingLocation];
}
- (void)locationManager:(CLLocationManager *)manager didUpdateLocations:(NSArray *)locations
{
if (startingPoint == nil) {
startingPoint = [locations lastObject];
NSLog(@"first time -- locations.count = %d", locations.count);
distanceTraveled = 0;
distanceTraveledLabel.text = @"0m";
}
else if (locations.count > 1) {
NSLog(@"into the else if -- locations.count = %d", locations.count);
lastLocation = locations[locations.count -2];
distanceTraveled = distanceTraveled + [currentLocation distanceFromLocation:lastLocation];
distanceTraveledLabel.text = [NSString stringWithFormat:@"%gm", distanceTraveled];
}
NSLog(@"locations.count = %d", locations.count);
currentLocation = [locations lastObject];
latitudeLabel.text =
[NSString stringWithFormat:@"%g\u00B0", currentLocation.coordinate.latitude];
longitudeLabel.text =
[NSString stringWithFormat:@"%g\u00B0", currentLocation.coordinate.longitude];
horizontalAccuracyLabel.text =
[NSString stringWithFormat:@"%gm", currentLocation.horizontalAccuracy];
verticalAccuracyLabel.text =
[NSString stringWithFormat:@"%gm", currentLocation.verticalAccuracy];
altitudeLabel.text =
[NSString stringWithFormat:@"%gm", currentLocation.altitude];
}
- (void)locationManager:(CLLocationManager *)manager didFailWithError:(NSError *)error
{
NSString *errorString = [[NSString alloc] init];
switch (error.code) {
case kCLErrorLocationUnknown:
errorString = @"Location unknown";
break;
case kCLErrorDenied:
errorString = @"Access denied";
break;
case kCLErrorNetwork:
errorString = @"No network coverage";
break;
case kCLErrorDeferredAccuracyTooLow:
errorString = @"Accuracy is too low to display";
break;
default:
break;
}
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Error getting location"
message:errorString
delegate:nil
cancelButtonTitle:@"OK"
otherButtonTitles:nil];
[alert show];
}
@end
这是记录器的外观像这样：
This is what the logger looks like:
2012-11-21 11:28:34.882 WhereAmI[652:11c03] first time -- locations.count = 1
2012-11-21 11:28:34.897 WhereAmI[652:11c03] locations.count = 1
2012-11-21 11:28:35.835 WhereAmI[652:11c03] locations.count = 1
2012-11-21 11:28:36.835 WhereAmI[652:11c03] locations.count = 1
2012-11-21 11:28:37.836 WhereAmI[652:11c03] locations.count = 1
2012-11-21 11:28:38.836 WhereAmI[652:11c03] locations.count = 1
2012-11-21 11:28:39.837 WhereAmI[652:11c03] locations.count = 1
2012-11-21 11:28:40.837 WhereAmI[652:11c03] locations.count = 1
2012-11-21 11:28:41.838 WhereAmI[652:11c03] locations.count = 1
2012-11-21 11:28:42.839 WhereAmI[652:11c03] locations.count = 1
以此类推...
有什么建议吗？谢谢大家，并一如既往地为英语不好而感到抱歉！
Any advice? Thanks everyone and, as always, sorry for the bad english!
推荐答案
模拟器不会返回一个以上的位置，因为它使用了计算机的位置信息，因此您可以获得Wi-Fi的精度，仅此而已，除非在运行时更改为其他地方的另一个Wi-Fi网络，否则它绝不能返回更准确的位置。
Simulator will not return more than one location since it uses the location of your computer, so you get the precision of your Wi-Fi and that's it unless you change to another Wi-Fi network somewhere else while running it should never return a more accuracy/different location.
如果您正在移动的实际设备上进行测试，或者该设备首先为您提供了信号塔的精度，然后是Wi-Fi，然后是GPS精度，
If you're testing on an actual device that moves, or if the device first gives you the cell tower accuracy, then Wi-Fi, then GPS accuracy you will receive more than one location in the array.
希望这可以清除它。
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