Ios Select语句解析目标C

我刚刚开始开发“客观分析”。 我的应用程序中有一个功能，允许用户进入新的爬升。 数据在解析时存储在我的一个表中。我将这个爬升添加到我的应用程序的地图视图部分

我想编写一个select语句，将查询的所有结果存储到某种数组中，然后将其转储到映射视图部分。通过这种方式，我认为它会在每次添加新区域时动态地向地图添加一个地图pin，当然，如果它还不存在的话

我是一名.net开发人员，在这个场景中，我会获取所有数据，然后将其转储到数据表中，然后从那里开始使用它。。。。但我不确定在目标c中的上述场景中实现这一点的最佳实践

我将在下面发布我的地图代码：

MapPin.h

MapViewController.h

MapViewController.m

---

很抱歉在这里转储了很多代码。。。只是想给大家提供我所拥有的。

在回答之前，请注意： 启动方法小写，这是一种常见的做法。 pin和注释是两个不同的概念，假设pin是视图，而注释是模型或业务对象，因此最好像MapAnnontation一样调用MapPin，或者只调用Annontation，因为Map是多余的。可能在不久的将来，您将拥有自定义管脚，这是MKAnnotationView的一个子类

对于您的回复，我有一个从www.sharewifiapp.com解析中检索当前地图区域位置的应用程序。这是代码，下面是一些说明：

#pragma mark MKMapViewDelegate
- (void)mapView:(MKMapView *)mapView regionWillChangeAnimated:(BOOL)animated {
    [self.hotspotsQuery cancel];
}

- (void)mapView:(MKMapView *)mapView regionDidChangeAnimated:(BOOL)animated {

    //DDDebugLog(@"zoom %lu", (unsigned long)[self.mapView zoomLevel]);

    // retrieve all hotspots using the filtering and the current view port
    self.hotspotsQuery = [PFQuery queryWithClassName:[SWHotspot parseClassName]];
    MKMapRect mRect = self.mapView.visibleMapRect;
    MKMapPoint neMapPoint = MKMapPointMake(MKMapRectGetMaxX(mRect), mRect.origin.y);
    MKMapPoint swMapPoint = MKMapPointMake(mRect.origin.x, MKMapRectGetMaxY(mRect));
    CLLocationCoordinate2D neCoord = MKCoordinateForMapPoint(neMapPoint);
    CLLocationCoordinate2D swCoord = MKCoordinateForMapPoint(swMapPoint);
    PFGeoPoint* swGeoPoint=[PFGeoPoint geoPointWithLatitude:swCoord.latitude longitude:swCoord.longitude];
    PFGeoPoint* neGeoPoint=[PFGeoPoint geoPointWithLatitude:neCoord.latitude longitude:neCoord.longitude];
    [self.hotspotsQuery whereKey:@"location" withinGeoBoxFromSouthwest:swGeoPoint toNortheast:neGeoPoint];
    [self.hotspotsQuery includeKey:@"owner"];
    [self.hotspotsQuery orderByDescending:@"updatedAt"];
    self.hotspotsQuery.limit=1000;


    self.loadingHotspotsActivityView.hidden=NO;
    [self.hotspotsQuery findObjectsInBackgroundWithBlock:^(NSArray *hotspots, NSError *error) {

        self.loadingHotspotsActivityView.hidden=YES;
        if (error) {
            DDLogError(@"Error retrieving hotspots: %@", [error userInfo][@"error"]);

        } else {
            // TEST. 
            /*
            NSLog(@"retrieved: %lu", (unsigned long)objects.count);
            [self.mapView removeAnnotations:self.mapView.annotations];
            [self.mapView addAnnotations:objects];
            */



                // remove hotspots that are not in the current response (hotstpots)
                NSMutableArray* hotspotsToRemove=[self.mapView.annotations mutableCopy];
                [hotspotsToRemove removeObjectsInArray:hotspots];
                [self.mapView removeAnnotations:hotspotsToRemove];

                // add hotpots from the current response that were not in the original set
                NSMutableArray* hotspotsToAdd=[hotspots mutableCopy];
                [hotspotsToAdd removeObjectsInArray:self.mapView.annotations];
                [self.mapView addAnnotations:hotspotsToAdd];

        }
    }];
}

要点： -保存解析查询，以便取消它。 -当用户开始移动地图时取消，当用户停止移动地图时启动新请求。 -每次从解析查询接收到新位置时，您都可以删除所有注释并放置新注释，但从性能角度来看，这并不好。如果你想试试我的代码，上面写着TEST。 -如果要提高性能，请遵循我的逻辑，即删除不在当前回复中的注释，并且仅在它们不在映射中时添加新位置

希望这有帮助

#import "MapPin.h"

@implementation MapPin

@synthesize coordinate, title, subtitle;

@end

#import <UIKit/UIKit.h>
#import <MapKit/MapKit.h>

@interface MapViewController : UIViewController
{
    MKMapView *mapView;
}

@property (nonatomic, retain) IBOutlet MKMapView *mapView;

-(IBAction)SetMap:(id)sender;

-(IBAction)GetLocation:(id)sender;

-(IBAction)Directions:(id)sender;

@end

#import "MapViewController.h"
#import "MapPin.h"

@interface MapViewController ()<MKMapViewDelegate>

@end

@implementation MapViewController

@synthesize mapView;

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
    // Custom initialization
    }
    return self;
}

- (void)viewDidLoad
{
[super viewDidLoad];

mapView.delegate = self;

//new
//[self.mapView setShowsUserLocation:YES];

//Moss Preserve annotation and map pin
MapPin *MossPreserveAnnotation = [[MapPin alloc] init];
MossPreserveAnnotation.title = @"Moss Rock Preserve Boulder Fields";
MossPreserveAnnotation.subtitle = @"Hoover, AL";
MossPreserveAnnotation.coordinate = CLLocationCoordinate2DMake(33.3816566, -86.8415451);
[mapView addAnnotation:MossPreserveAnnotation];

 //Setup map
MKCoordinateRegion mapCoordRegion;
mapCoordRegion.center.latitude = 39;
mapCoordRegion.center.longitude = -97;
mapCoordRegion.span.latitudeDelta = 60.0;
mapCoordRegion.span.longitudeDelta = 60.0;

[mapView setRegion:mapCoordRegion];
}

- (void)viewWillAppear:(BOOL)animated
{
[super viewWillAppear:animated];

[[UIApplication sharedApplication] setStatusBarStyle:UIStatusBarStyleDefault];
self.navigationController.navigationBar.hidden = NO;
}


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

- (void)mapView:(MKMapView *)mapView annotationView:(MKAnnotationView *)view calloutAccessoryControlTapped:(UIControl *)control
{

// Create an MKMapItem to pass to the Maps app
MKPlacemark *placemark = [[MKPlacemark alloc]  initWithCoordinate:view.annotation.coordinate
                                                addressDictionary:nil];
MKMapItem *MapItem = [[MKMapItem alloc] initWithPlacemark:placemark];
[MapItem setName:view.annotation.title];

NSDictionary *launchOptions = @{MKLaunchOptionsDirectionsModeKey : MKLaunchOptionsDirectionsModeDriving};

// Get the "Current User Location" MKMapItem
MKMapItem *currentLocationItem = [MKMapItem mapItemForCurrentLocation];
[MKMapItem openMapsWithItems:@[currentLocationItem, MapItem]
               launchOptions:launchOptions];
}

- (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id<MKAnnotation>)annotation
{
MKAnnotationView *annotationView = [[MKPinAnnotationView alloc] initWithAnnotation:annotation
                                                                   reuseIdentifier:@"MKPinAnnotationView"];
annotationView.canShowCallout = YES;

UIButton *detailButton = [UIButton buttonWithType:UIButtonTypeInfoLight];
[detailButton setTintColor:[UIColor colorWithRed:183/255.0 green:207/255.0 blue:85/255.0 alpha:0.5]];

annotationView.rightCalloutAccessoryView = detailButton;

return annotationView;
}

-(IBAction)SetMap:(id)sender;
{
switch (((UISegmentedControl *) sender).selectedSegmentIndex)
{
    case 0:
        mapView.mapType = MKMapTypeStandard;
        break;
    case 1:
        mapView.mapType = MKMapTypeSatellite;
        break;
    case 2:
        mapView.mapType = MKMapTypeHybrid;
        break;

    default:
        break;
}
}

-(IBAction)GetLocation:(id)sender;
{
mapView.showsUserLocation = YES;
}

-(IBAction)Directions:(id)sender;
{
NSString *urlString = @"http://maps.apple.com/maps?daddr=33.3816566,-86.8415451";
[[UIApplication sharedApplication] openURL:[NSURL URLWithString:urlString]];
}

@end

#pragma mark MKMapViewDelegate
- (void)mapView:(MKMapView *)mapView regionWillChangeAnimated:(BOOL)animated {
    [self.hotspotsQuery cancel];
}

- (void)mapView:(MKMapView *)mapView regionDidChangeAnimated:(BOOL)animated {

    //DDDebugLog(@"zoom %lu", (unsigned long)[self.mapView zoomLevel]);

    // retrieve all hotspots using the filtering and the current view port
    self.hotspotsQuery = [PFQuery queryWithClassName:[SWHotspot parseClassName]];
    MKMapRect mRect = self.mapView.visibleMapRect;
    MKMapPoint neMapPoint = MKMapPointMake(MKMapRectGetMaxX(mRect), mRect.origin.y);
    MKMapPoint swMapPoint = MKMapPointMake(mRect.origin.x, MKMapRectGetMaxY(mRect));
    CLLocationCoordinate2D neCoord = MKCoordinateForMapPoint(neMapPoint);
    CLLocationCoordinate2D swCoord = MKCoordinateForMapPoint(swMapPoint);
    PFGeoPoint* swGeoPoint=[PFGeoPoint geoPointWithLatitude:swCoord.latitude longitude:swCoord.longitude];
    PFGeoPoint* neGeoPoint=[PFGeoPoint geoPointWithLatitude:neCoord.latitude longitude:neCoord.longitude];
    [self.hotspotsQuery whereKey:@"location" withinGeoBoxFromSouthwest:swGeoPoint toNortheast:neGeoPoint];
    [self.hotspotsQuery includeKey:@"owner"];
    [self.hotspotsQuery orderByDescending:@"updatedAt"];
    self.hotspotsQuery.limit=1000;


    self.loadingHotspotsActivityView.hidden=NO;
    [self.hotspotsQuery findObjectsInBackgroundWithBlock:^(NSArray *hotspots, NSError *error) {

        self.loadingHotspotsActivityView.hidden=YES;
        if (error) {
            DDLogError(@"Error retrieving hotspots: %@", [error userInfo][@"error"]);

        } else {
            // TEST. 
            /*
            NSLog(@"retrieved: %lu", (unsigned long)objects.count);
            [self.mapView removeAnnotations:self.mapView.annotations];
            [self.mapView addAnnotations:objects];
            */



                // remove hotspots that are not in the current response (hotstpots)
                NSMutableArray* hotspotsToRemove=[self.mapView.annotations mutableCopy];
                [hotspotsToRemove removeObjectsInArray:hotspots];
                [self.mapView removeAnnotations:hotspotsToRemove];

                // add hotpots from the current response that were not in the original set
                NSMutableArray* hotspotsToAdd=[hotspots mutableCopy];
                [hotspotsToAdd removeObjectsInArray:self.mapView.annotations];
                [self.mapView addAnnotations:hotspotsToAdd];

        }
    }];
}