我有一个搜索设置，它在 UITableVIew 中显示 MKLocalSearchRequest 的响应

我想从每次搜索的响应中清除所有 响应。到目前为止，这是我在这篇文章的启发下实现的目标 Multiple Locations on Map (using MKMapItem and CLGeocoder)

这是我的代码。

@interface ViewController () <UISearchBarDelegate,UISearchDisplayDelegate,UITextFieldDelegate>
@property (nonatomic, strong) UISearchDisplayController *searchController;
@property (nonatomic, strong) UISearchBar *searchBar;

@property (nonatomic, strong) MKLocalSearch *localSearch;
@property (nonatomic, strong) MKLocalSearchResponse *localSearchResponse;

@property (nonatomic, strong) NSArray *dirtyResponseArray;
@property (nonatomic, strong) NSMutableArray *geocodedResultsArray;
@end

@implementation ViewController

-(void)startSearch:(NSString *)searchString
{
    if (self.localSearch.searching)
        [self.localSearch cancel];

    MKLocalSearchRequest *request = [[MKLocalSearchRequest alloc] init];
    request.naturalLanguageQuery = searchString;
    request.region = MKCoordinateRegionMake(self.currentLocation.coordinate, self.mapView.region.span);

    MKLocalSearchCompletionHandler completionHandler = ^(MKLocalSearchResponse *response, NSError *error){

        if (error != nil) return;

        else {
            self.dirtyResponseArray = response.mapItems;                
            [self operation];
            [self.searchController.searchResultsTableView reloadData];
            [UIApplication sharedApplication].networkActivityIndicatorVisible = NO;
        }

        [self.searchDisplayController.searchResultsTableView reloadData];
    };

    if (self.localSearch != nil)
        self.localSearch = nil;

    self.localSearch = [[MKLocalSearch alloc] initWithRequest:request];
    [self.localSearch startWithCompletionHandler:completionHandler];
}

-(void)operation
{
    CLGeocoder *geocoder = [[CLGeocoder alloc]init];
    NSOperationQueue *queue = [[NSOperationQueue alloc] init];

    NSOperation *finalCompletionOperation = [NSBlockOperation blockOperationWithBlock:^{
        [MKMapItem openMapsWithItems:self.geocodedResultsArray launchOptions:nil];
        NSLog(@"Local Search Response To use in tableview =================== %@", self.geocodedResultsArray);
    }];

    NSOperation *previousCompletionHandler = nil;

    //Issue is probably right here. How should I handle the MKMapItem in the array?
    //NSString *address = [self.dirtyResponseArray valueForKey:@"address"][@"formattedAddress"]; ??

    for (NSString *address in self.dirtyResponseArray) {

        NSBlockOperation *geocodeRequest = [[NSBlockOperation alloc] init];
        if (previousCompletionHandler) [geocodeRequest addDependency:previousCompletionHandler];
        NSBlockOperation *geocodeCompletionHandler = [[NSBlockOperation alloc] init];
        [finalCompletionOperation addDependency:geocodeCompletionHandler];

        [geocodeRequest addExecutionBlock:^{ [geocoder geocodeAddressString:address 
                        completionHandler:^(NSArray *placemarks, NSError *error) 
        {
                [geocodeCompletionHandler addExecutionBlock:^{
                    if (error) NSLog(@"%@", error);

                    else if ([placemarks count] > 0)
                    {
                        CLPlacemark *geocodedPlacemark = [placemarks objectAtIndex:0];

                        MKPlacemark *placemark = [[MKPlacemark alloc] initWithCoordinate:geocodedPlacemark.location.coordinate
                                                                       addressDictionary:geocodedPlacemark.addressDictionary];

                        MKMapItem *mapItem = [[MKMapItem alloc] initWithPlacemark:placemark];
                        [mapItem setName:geocodedPlacemark.name];
                        [self.geocodedResultsArray addObject:mapItem];
                    }
                }];
                [queue addOperation:geocodeCompletionHandler];
            }];
        }];
        [queue addOperation:geocodeRequest];
        previousCompletionHandler = geocodeCompletionHandler;
    }
    [queue addOperation:finalCompletionOperation];
}
@end

我不确定如何处理每个 MKMapItem。现在它抛出这个错误

 -[MKMapItem length]: unrecognized selector sent to instance 0x7f813c9c6200

最佳答案

该问题中引用的 CLGeocoder 方法 geocodeAddressString 旨在对地址进行地理编码。

但是您正在特定区域内执行 MKLocalSearch，这会返回已进行地理编码的 MKMapItem 对象。因此，您可以从代码示例中完全删除 geocodeAddressString 代码。

事实上，这解释了异常的来源，即您正在获取 MKLocalSearch 返回的 MKMapItem，并尝试将其用作的搜索字符串参数CLGeocoder 方法geocodeAddressString(仅用于查找地址的字符串表示形式)。

最重要的是，进行本地搜索并在 map 应用程序中显示结果比您在上面考虑的要容易得多。您需要做的就是:

MKLocalSearchRequest *request = [[MKLocalSearchRequest alloc] init];
request.naturalLanguageQuery = searchString;
request.region = region;
MKLocalSearch *search = [[MKLocalSearch alloc] initWithRequest:request];

[search startWithCompletionHandler:^(MKLocalSearchResponse *response, NSError *error) {
    [MKMapItem openMapsWithItems:response.mapItems launchOptions:nil];
}];

或者，如果你想在你自己的 MKMapView 上显示它，你可以做类似的事情

MKLocalSearchRequest *request = [[MKLocalSearchRequest alloc] init];
request.naturalLanguageQuery = searchString;
request.region = region;
MKLocalSearch *search = [[MKLocalSearch alloc] initWithRequest:request];

[search startWithCompletionHandler:^(MKLocalSearchResponse *response, NSError *error) {
    for (MKMapItem *item in response.mapItems) {
        [self.mapView addAnnotation:item.placemark];
    }
}];

实际上，在后一个示例中，您在自己的 map View 上显示结果，您可以创建自己的自定义注释类，以便更好地控制 viewForAnnotation方法。但希望这能说明主要观察结果，即在使用 MKLocalSearch 时，您根本不应该使用 CLGeocoder 方法 geocodeAddressString。

关于ios - 批量地理编码 MKLocalSearch 响应，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/25438928/