iOS:当数据来自网络服务作为响应时，如何获取多个经度和纬度的位置名称？

Question

我需要帮助我的代码。我正在获取经度和纬度作为网络服务的响应。我需要将它们转换为位置名称并将其显示在相应的表格 View 单元格标签中。
以下是我的 View 的响应、代码和屏幕截图，其中我显示了我转换后的城市、国家/地区名称，并在我出错的地方更正了我的代码。

#import <UIKit/UIKit.h>
#import "JobTableViewCell.h"
#import "SlideNavigationController.h"
#import <CoreLocation/CoreLocation.h>

@interface JobPostedViewController : UIViewController <SlideNavigationControllerDelegate, UITableViewDataSource, CLLocationManagerDelegate>

@property (strong, nonatomic) NSArray* job_id;
@property (strong, nonatomic) NSArray* assigned_user_id;
@property (strong, nonatomic) NSArray* job_title;
@property (strong, nonatomic) NSArray* job_description;
@property (strong, nonatomic) NSArray* job_priority;
@property (strong, nonatomic) NSString* job_longitude;
@property (strong, nonatomic) NSArray* date;
@property (strong, nonatomic) NSString* job_latitude;
@property (strong, nonatomic) NSArray* job_completed;
@property (strong, nonatomic) NSArray* job_start_date;
@property (strong, nonatomic) NSArray* bids;

@property (nonatomic, strong) CLGeocoder *myGeocoder;

- (IBAction)onClickJobButton:(id)sender;


@property (weak, nonatomic) IBOutlet UIButton *sideNavigation;
@property (weak, nonatomic) IBOutlet UITableView *jobPostedTableView;

@end
`

    - (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view.
    self.jobPostedTableView.dataSource = self;

    //Slide Navigation
    [self.sideNavigation addTarget:[SlideNavigationController sharedInstance] action:@selector(toggleLeftMenu) forControlEvents:UIControlEventTouchUpInside];

    WebManager *manager = [WebManager sharedInstance];
    [manager getJobPostedWithCompletionBlock:^(id response){
        NSDictionary *dictionary = (NSDictionary *)response;

        // Read data from JSON
        NSDictionary *responseObject = [dictionary objectForKey:@"response"];
        NSLog(@"The Array%@",responseObject);

        self.bids = [responseObject objectForKey:@"bids"];
        self.job_description = [responseObject objectForKey:@"job_description"];
        self.job_id = [responseObject objectForKey:@"job_id"];
        self.job_completed = [responseObject objectForKey:@"job_completed"];
        self.job_latitude = [responseObject objectForKey:@"job_latitude"];
        self.job_longitude = [responseObject objectForKey:@"job_longitude"];
        self.job_priority = [responseObject objectForKey:@"job_priority"];
        self.job_start_date = [responseObject objectForKey:@"job_start_date"];
        self.job_title = [responseObject objectForKey:@"job_title"];

        [self.jobPostedTableView reloadData];
    }];

        CLGeocoder *ceo = [[CLGeocoder alloc]init];
        CLLocation *loc = [[CLLocation alloc]initWithLatitude:[self.job_latitude floatValue] longitude:[self.job_longitude floatValue]]; //insert your coordinates

        [ceo reverseGeocodeLocation:loc
                  completionHandler:^(NSArray *placemarks, NSError *error) {
                      CLPlacemark *placemark = [placemarks objectAtIndex:0];
                      NSLog(@"placemark %@",placemark);
                      //String to hold address
                      [[placemark.addressDictionary valueForKey:@"FormattedAddressLines"] componentsJoinedByString:@", "];
                      NSLog(@"addressDictionary %@", placemark.addressDictionary);
                      NSArray *ar = [placemark.addressDictionary objectForKey:@"locality"];
                      NSLog(@"placemark %@",ar); // Extract the city name
                      NSLog(@"placemark %@",placemark.country);  // Give Country Name

                  }

         ];
    }


#pragma mark - SlideNavigationController Methods

- (BOOL)slideNavigationControllerShouldDisplayLeftMenu
{

    return YES;
}

#pragma mark - TableView Data Source

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    return [self.job_title count];
}

- (NSInteger) numberOfSectionsInTableview:(UITableView *)tableView
{
    return 1;
}

- (UITableViewCell *) tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *cellIdentifier = @"JobTableViewCell";
    JobTableViewCell *cell = (JobTableViewCell *)[self.jobPostedTableView dequeueReusableCellWithIdentifier:cellIdentifier];

    if(cell == nil) {

        cell = [[JobTableViewCell alloc]initWithStyle:UITableViewCellStyleDefault reuseIdentifier:cellIdentifier];
    }
    // Comparing array string to display an urgent image
    if ([[self.job_priority objectAtIndex:indexPath.row]
         isEqualToString:@"urgent"]) {
        cell.urgentLabel.hidden = NO;
    } else {
            cell.urgentLabel.hidden = YES;
    }
    // Condition whether job completed is open or closed
    if ([[self.job_completed objectAtIndex:indexPath.row]
         isEqualToString:@"1"]) {
        cell.jobStatus.text = @"Open";
        [cell.jobStatus setTextColor:[UIColor colorWithRed:(84/255.f) green:(56/255.f) blue:(255/255.f) alpha:1.0f]];
        cell.flagImage.image = [UIImage imageNamed:@"jobPosted_opened.PNG"];
    } else {
        cell.jobStatus.text = @"Closed";
        [cell.jobStatus setTextColor:[UIColor colorWithRed:(179/255.f) green:(179/255.f) blue:(180/255.f) alpha:1.0f]];
        cell.flagImage.image = [UIImage imageNamed:@"jobPosted_closed.PNG"];
    }


    cell.jobTitle.text = [self.job_title objectAtIndex:indexPath.row];
    cell.jobContent.text = [self.job_description objectAtIndex:indexPath.row];
    cell.bidsLabel.text = [[self.bids objectAtIndex:indexPath.row ]stringValue];
    return cell;

}


- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

Answer 1

解决方法如下:

1. 将这些属性的NSString更改为NSArray:

   @property (strong, nonatomic) NSString* job_longitude;
   @property (strong, nonatomic) NSString* job_latitude;
   

---

1. 添加一个新的属性来保存地理编码结果:

   @property (strong, nonatomic) NSMutableDictionary* reversedGeocodes;
   

---

1. 在viewDidLoad:方法中设置reversedGeocodes:

   self.reversedGeocodes = [NSMutableDictionary dictionary];
   

---

1. 添加此方法以获取反向地理代码(并保存以备将来使用):

   - (void)locationNameWithLat:(float)lat
                           lng:(float)lng
             completionHandler:(void (^)(NSString *locationName, NSError *error))completion
   {
       if (!lat || !lng)
           completion(@"Unknown location", nil);
   
       if (!completion || !lat || !lng)
           return;
   
       NSString *latStr = @(lat).description;
       NSString *lngStr = @(lng).description;
   
       // For each pair of lat and lng creating a unique key and saving the result
       // so we don't have to process the same pair multiple times.
       // Example:
       // lat = 23.039567; lng = 72.566004;
       // key = @"23.03956772.566004"; value would be whatever CoreLocation returns
       NSString *key = [latStr stringByAppendingString:lngStr];
   
       if (key.length) {
           if ([self.reversedGeocodes[key] length]) {
               completion (self.reversedGeocodes[key], nil);
           } else {
               self.reversedGeocodes[key] = @"Loading...";
               CLGeocoder *geocoder = [[CLGeocoder alloc] init];
               CLLocation *location = [[CLLocation alloc] initWithLatitude:lat longitude:lng];
   
               [geocoder reverseGeocodeLocation:location
                              completionHandler:^(NSArray *placemarks, NSError *error) {
                                  if (error) {
                                      completion(@"Unknown location", error);
                                  } else {
                                      CLPlacemark *placemark = placemarks.firstObject;
                                      NSString *locationName = placemark.country; // Default = country
   
                                      if (placemark.locality.length) // add city if available
                                          locationName = [NSString stringWithFormat:@"%@, %@", placemark.locality, placemark.country];
   
                                      self.reversedGeocodes[key] = locationName.length ? locationName : @"Unknown location";
   
                                      completion(self.reversedGeocodes[key], nil);
                                  }
                              }
                ];
           }
       } else {
           completion(@"Unknown location", nil);
       }
   }
   

---

1. 在返回 cell 之前从 cellForRowAtIndexPat: 方法调用上述方法:

   float lat = self.job_latitude[indexPath.row];
   float lng = self.job_longitude[indexPath.row];
   
   [self locationNameWithLat:lat
                         lng:lng
           completionHandler:^(NSString *locationName, NSError *error) {
               cell.locationName.text = locationName;
           }];
   
   return cell;
   

---

附言让我知道是否因为我在这里输入了一些代码而遗漏了任何内容或拼写错误...