我已经设法通过使用this获得当前位置。之后，我试图将lat和long作为字符串传递给另一个加载webview的方法。问题是每次加载此VC时，都不会调用以下方法
-(void)locationManager:(CLLocationManager *)manager didUpdateLocations:(NSArray *)locations
并立即跳转到以下方法。
-(void)viewWillAppear:(BOOL)animated
如何获取位置并将其存储为变量，将它们作为字符串传递给另一个方法，附加一个字符串并将其传递给NSURL并加载webview？
是拉特和长期保留？如何在整个项目中保留它？
单击其他选项卡控制器并单击此VC时会发生什么。 lat和long是否会再次刷新？
- (void)viewDidLoad
{
[super viewDidLoad];
geocoder = [[CLGeocoder alloc] init];
if (locationManager == nil)
{
locationManager = [[CLLocationManager alloc] init];
locationManager.desiredAccuracy = kCLLocationAccuracyNearestTenMeters;
locationManager.delegate = self;
[locationManager requestAlwaysAuthorization];
}
[locationManager startUpdatingLocation];
dtDate = [[NSMutableArray alloc] init];
self.currentPageIndex = 0;
self.hasAppearedFlag = NO;
}
//=== It doesn't call a following method first.
- (void)locationManager:(CLLocationManager *)manager didUpdateLocations:(NSArray *)locations {
CLLocation *newLocation = [locations lastObject];
[geocoder reverseGeocodeLocation:newLocation completionHandler:^(NSArray *placemarks, NSError *error) {
if (error == nil && [placemarks count] > 0) {
placemark = [placemarks lastObject];
latitude = [NSString stringWithFormat:@"%f",newLocation.coordinate.latitude];
longitude = [NSString stringWithFormat:@"%f",newLocation.coordinate.longitude];
state = placemark.administrativeArea;
country = placemark.country;
NSLog(@"This is the latitude%@", latitude);
NSLog(@"This is the longitude%@", longitude);
} else {
NSLog(@"This is the error debug%@", error.debugDescription);
}
}];
// Turn off the location manager to save power.
[manager stopUpdatingLocation];
//*** It will start loading this part below
[self setupSegmentButtons];
NSDate *now = [NSDate date];
NSDateFormatter *dateFormatter=[[NSDateFormatter alloc] init];
[dateFormatter setDateFormat:@"dd/MM/YYYY"];
NSString *dateString = [dateFormatter stringFromDate:now];
[self LoadClasses:dateString];
self.hasAppearedFlag = YES;
}
- (void)locationManager:(CLLocationManager *)manager
didFailWithError:(NSError *)error
{
NSLog(@"Cannot find the location.");
}
//=== Load webview
- (void)LoadClasses : (NSString *)sDate{
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
sMemCode = [defaults objectForKey:@"txtMemCode"];
NSLog(@"Load Class This is the memCode:%@", sMemCode);
NSLog(@"Load Class This is the latitude:%@", latitude);
NSLog(@"Load Class This is the longitude:%@", longitude);
appDelegate = (AppDelegate *)[[UIApplication sharedApplication] delegate];
sURL = appDelegate.gURL;
sURL = [sURL stringByAppendingString:@"/apps/class.asp?"];
sURL = [sURL stringByAppendingString:@"memCode="];
sURL = [sURL stringByAppendingString:sMemCode];
sURL = [sURL stringByAppendingString:@"&dtpClass="];
sURL = [sURL stringByAppendingString:sDate];
sURL = [sURL stringByAppendingString:@"&lat="];
sURL = [sURL stringByAppendingString:latitude];
sURL = [sURL stringByAppendingString:@"&long="];
sURL = [sURL stringByAppendingString:longitude];
NSLog(@" The sURL to load for the current page : %@ ", sURL);
NSURL *url = [NSURL URLWithString:sURL];
NSURLRequest *urlRequest = [NSURLRequest requestWithURL:url];
[webView loadRequest:urlRequest];
[webView setDelegate:(id<UIWebViewDelegate>)self];
}
I have put the `Location Delegates` to `AppDelegates`
AppDelegates.h
#import <UIKit/UIKit.h>
#import<CoreLocation/CoreLocation.h>
@interface AppDelegate : UIResponder <UIApplicationDelegate>{
CLLocationManager *locationManager;
}
@property (nonatomic, strong) NSString *slatitude;
@property (nonatomic, strong) NSString *slongitude;
@end
AppDelegates.m
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
//--- Get current location ---
if (locationManager == nil)
{
locationManager = [[CLLocationManager alloc] init];
locationManager.desiredAccuracy = kCLLocationAccuracyNearestTenMeters;
locationManager.delegate = self;
//-- Pop up authrorization to use current location ---
[locationManager requestAlwaysAuthorization];
}
[locationManager startUpdatingLocation];
}
- (void)locationManager: (CLLocationManager *)manager didUpdateToLocation: (CLLocation *)newLocation fromLocation: (CLLocation *)oldLocation
{
float latitude = newLocation.coordinate.latitude;
slatitude = [NSString stringWithFormat:@"%f",latitude];
float longitude = newLocation.coordinate.longitude;
slongitude = [NSString stringWithFormat:@"%f", longitude];
NSLog(@"App:This is the latitude%@", slatitude);
NSLog(@"App:This is the longitude%@", slongitude);
}
- (void)locationManager:(CLLocationManager *)manager
didFailWithError:(NSError *)error
{
NSLog(@"Cannot find the location.");
}
In any VC,
appDelegate = (AppDelegate *)[[UIApplication sharedApplication] delegate];
latitude = appDelegate.slatitude;
longitude = appDelegate.slongitude;
我建议你将你的位置代表代码移动到你的Appdelegate文件，以便它注册并不断更新位置委托方法，
您可以从appdelegate文件中创建两个属性变量，并在调用委托时继续更新它们，或者使用这样的getter或setter方法：
@interface AppDelegate : UIResponder<UILocationDelegate>{
CLLocationManager * locationManager;
}
@property (nonatomic, strong) NSString *lattitude;
@property (nonatomic, strong) NSString *longitude;
@end
@implementation AppDelegate
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions{
if (locationManager == nil)
{
locationManager = [[CLLocationManager alloc] init];
locationManager.desiredAccuracy = kCLLocationAccuracyNearestTenMeters;
locationManager.delegate = self;
[locationManager requestAlwaysAuthorization];
}
[locationManager startUpdatingLocation];
}
然后在这里实现位置委托方法
- (void)locationManager:(CLLocationManager *)manager didUpdateLocations:(NSArray *)locations {
if (error == nil && [placemarks count] > 0) {
placemark = [placemarks lastObject];
self.latitude = [NSString stringWithFormat:@"%f",newLocation.coordinate.latitude];
self.longitude = [NSString stringWithFormat:@"%f",newLocation.coordinate.longitude];
state = placemark.administrativeArea;
country = placemark.country;
NSLog(@"This is the latitude%@", latitude);
NSLog(@"This is the longitude%@", longitude);
}
}
- (void)locationManager:(CLLocationManager *)manager
didFailWithError:(NSError *)error
{
NSLog(@"Cannot find the location.");
}
迟到，你可以从ViewController访问它
- (void)viewDidAppear:(BOOL)animated {
AppDelegate* appdelegate = (AppDelegate*)[[UIApplication sharedApplication] delegate];
NSString *lat = appdelegate.lattitude;
NSString *long = appdelegate.longitude;
}
以这种方式即使您切换标签栏或更改控制器，您仍将拥有最新的位置。
实际上你在ViewWillAppear中调用你的方法并且你在didUpdateLocations中获取数据..之后ViewWillappear没有保证，更好的是你在收到数据后从didUpdateLocations调用你的方法