在 iOS 中,我这样声明 CLLocationManager 变量:
DashBoardViewController.h
#import <UIKit/UIKit.h>
#import <CoreLocation/CoreLocation.h>
@class AppDelegate;
@interface DashBoardViewController : UIViewController<CLLocationManagerDelegate, UIAlertViewDelegate>{
AppDelegate *appDel;
}
@property(nonatomic,strong) CLLocationManager *locationManager;
@property (nonatomic,retain) CLLocation *current;
-(void)localnotification;
@end
在 DashBoardViewController.m 文件中:
#import "DashBoardViewController.h"
#import "AppDelegate.h"
#define IS_OS_8_OR_LATER ([[[UIDevice currentDevice] systemVersion] floatValue] >= 8.0)
@interface DashBoardViewController ()
@end
@implementation DashBoardViewController
@synthesize current,locationManager;
- (void)viewDidLoad
{
[super viewDidLoad];
appDel = (AppDelegate*)[UIApplication sharedApplication].delegate;
[self localnotification];
}
-(void)localnotification{
locationManager = [[CLLocationManager alloc] init];
locationManager.delegate = self;
locationManager.distanceFilter = kCLDistanceFilterNone;
locationManager.desiredAccuracy = kCLLocationAccuracyBest;
if(IS_OS_8_OR_LATER) {
[locationManager requestAlwaysAuthorization];
}
[locationManager startMonitoringSignificantLocationChanges];
}
我也实现了
- (void)locationManager:(CLLocationManager *)manager didUpdateLocations:(NSArray *)locations
{
//some code
}
现在我正在访问 "locationManager" 和 "localnotification" 方法,如下所示 设置 View Controller .m
#import <UIKit/UIKit.h>
#import <CoreLocation/CoreLocation.h>
#import "DashBoardViewController.h"
//To stop the Location Manager service
- (IBAction)stopButtonAction:(id)sender {
DashBoardViewController *dash=[[DashBoardViewController alloc] init];
dash.locationManager=nil;
}
//To start the Location Manager service
- (IBAction)startButtonAction:(id)sender {
DashBoardViewController *dash=[[DashBoardViewController alloc] init];
[dash localnotification];
}
但它不起作用。所有时间 locationManager 返回 null。这段代码有什么问题?
最佳答案
当你
DashBoardViewController *dash=[[DashBoardViewController alloc] init];
它创建一个新的 DashBoardViewController
实例。您可以在 AppDelegate
中定义 locationManager
并从代码中的任何位置直接访问它。
AppDelegate *appDelegate = (AppDelegate *)[[UIApplication sharedApplication] delegate];
appDelegate.locationManager = nil;
关于ios - 从一个 View Controller 访问 CLLocationManager 变量到另一个 View Controller ,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/27487437/