• MapSearch 阅读随笔


    MapSearch

    https://developer.apple.com/library/ios/samplecode/MapSearch/Introduction/Intro.html#//apple_ref/doc/uid/DTS40013332

    //1.#import <MapKit/MapKit.h> //引入头文件
    #import <CoreLocation/CoreLocation.h>
    //遵循协议
    <CLLocationManagerDelegate, UISearchBarDelegate>

    //2. 声明 属性
    @interface MyTableViewController ()
    @property (nonatomic, assign) MKCoordinateRegion boundingRegion;
    @property (nonatomic, strong) MKLocalSearch *localSearch;
    @property (nonatomic, weak) IBOutlet UIBarButtonItem *viewAllButton;
    @property (nonatomic, strong) CLLocationManager *locationManager;
    @property (nonatomic) CLLocationCoordinate2D userCoordinate;
    @property (weak, nonatomic) IBOutlet UISearchBar *searchBar;

    @end

    //3. 初始化 locationManager
    - (void)viewDidLoad {
    [super viewDidLoad];

    self.locationManager = [[CLLocationManager alloc] init];
    }

    //4. UITableView delegate methods
    - (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
    return [self.places count];
    }

    - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:kCellIdentifier forIndexPath:indexPath];

    MKMapItem *mapItem = [self.places objectAtIndex:indexPath.row];
    cell.textLabel.text = mapItem.name;

    return cell;
    }

    //5.点击搜索按钮后执行
    - (void)searchBarSearchButtonClicked:(UISearchBar *)searchBar{
    // Check if location services are available
    if ([CLLocationManager locationServicesEnabled] == NO) {
    NSLog(@"%s: location services are not available.", __PRETTY_FUNCTION__);

    // Display alert to the user.
    UIAlertController *alert = [UIAlertController alertControllerWithTitle:@"Location services"
    message:@"Location services are not enabled on this device. Please enable location services in settings."
    preferredStyle:UIAlertControllerStyleAlert];
    UIAlertAction* defaultAction = [UIAlertAction actionWithTitle:@"Dismiss" style:UIAlertActionStyleDefault
    handler:^(UIAlertAction * action) {}]; // Do nothing action to dismiss the alert.

    [alert addAction:defaultAction];
    [self presentViewController:alert animated:YES completion:nil];

    return;
    }

    // Request "when in use" location service authorization.
    // If authorization has been denied previously, we can display an alert if the user has denied location services previously.
    if ([CLLocationManager authorizationStatus] == kCLAuthorizationStatusNotDetermined) {
    [self.locationManager requestWhenInUseAuthorization];
    } else if ([CLLocationManager authorizationStatus] == kCLAuthorizationStatusDenied) {
    NSLog(@"%s: location services authorization was previously denied by the user.", __PRETTY_FUNCTION__);

    // Display alert to the user.
    UIAlertController *alert = [UIAlertController alertControllerWithTitle:@"Location services"
    message:@"Location services were previously denied by the user. Please enable location services for this app in settings."
    preferredStyle:UIAlertControllerStyleAlert];
    UIAlertAction* defaultAction = [UIAlertAction actionWithTitle:@"Dismiss" style:UIAlertActionStyleDefault
    handler:^(UIAlertAction * action) {}]; // Do nothing action to dismiss the alert.

    [alert addAction:defaultAction];
    [self presentViewController:alert animated:YES completion:nil];

    return;
    }

    // Start updating locations.
    self.locationManager.delegate = self;
    [self.locationManager startUpdatingLocation];
    }

    //6. 获取定位信息后根据位置信息搜索周围地点
    - (void)locationManager:(CLLocationManager *)manager didUpdateLocations:(NSArray *)locations {

    // Remember for later the user's current location.
    CLLocation *userLocation = locations.lastObject;
    self.userCoordinate = userLocation.coordinate;

    [manager stopUpdatingLocation]; // We only want one update.

    manager.delegate = nil; // We might be called again here, even though we
    // called "stopUpdatingLocation", so remove us as the delegate to be sure.

    // We have a location now, so start the search.
    [self startSearch:self.searchBar.text];
    }

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

    // Confine the map search area to the user's current location.
    MKCoordinateRegion newRegion;
    newRegion.center.latitude = self.userCoordinate.latitude;
    newRegion.center.longitude = self.userCoordinate.longitude;

    // Setup the area spanned by the map region:
    // We use the delta values to indicate the desired zoom level of the map,
    // (smaller delta values corresponding to a higher zoom level).
    // The numbers used here correspond to a roughly 8 mi
    // diameter area.
    //
    newRegion.span.latitudeDelta = 0.112872;
    newRegion.span.longitudeDelta = 0.109863;

    MKLocalSearchRequest *request = [[MKLocalSearchRequest alloc] init];

    request.naturalLanguageQuery = searchString;
    request.region = newRegion;

    MKLocalSearchCompletionHandler completionHandler = ^(MKLocalSearchResponse *response, NSError *error) {
    if (error != nil) {
    NSString *errorStr = [[error userInfo] valueForKey:NSLocalizedDescriptionKey];
    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Could not find places"
    message:errorStr
    delegate:nil
    cancelButtonTitle:@"OK"
    otherButtonTitles:nil];
    [alert show];
    } else {
    self.places = [response mapItems];

    // Used for later when setting the map's region in "prepareForSegue".
    self.boundingRegion = response.boundingRegion;

    self.viewAllButton.enabled = self.places != nil ? YES : NO;

    [self.tableView reloadData];
    }
    [UIApplication sharedApplication].networkActivityIndicatorVisible = NO;
    };

    if (self.localSearch != nil) {
    self.localSearch = nil;
    }
    self.localSearch = [[MKLocalSearch alloc] initWithRequest:request];

    [self.localSearch startWithCompletionHandler:completionHandler];
    [UIApplication sharedApplication].networkActivityIndicatorVisible = YES;
    }

    //7.点击对应的cell 或者点击showAll 按钮 跳转到下一界面
    - (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
    MapViewController *mapViewController = segue.destinationViewController;

    if ([segue.identifier isEqualToString:@"showDetail"]) {
    // Get the single item.
    NSIndexPath *selectedItemPath = [self.tableView indexPathForSelectedRow];
    MKMapItem *mapItem = self.places[selectedItemPath.row];

    // Pass the new bounding region to the map destination view controller.
    MKCoordinateRegion region = self.boundingRegion;
    // And center it on the single placemark.
    region.center = mapItem.placemark.coordinate;
    mapViewController.boundingRegion = region;

    // Pass the individual place to our map destination view controller.
    mapViewController.mapItemList = [NSArray arrayWithObject:mapItem];

    } else if ([segue.identifier isEqualToString:@"showAll"]) {

    // Pass the new bounding region to the map destination view controller.
    mapViewController.boundingRegion = self.boundingRegion;

    // Pass the list of places found to our map destination view controller.
    mapViewController.mapItemList = self.places;
    }
    }

    //8. Adjust the map to zoom/center to the annotations we want to show.
    [self.mapView setRegion:self.boundingRegion animated:YES];


    //9. We add the placemarks here to get the "drop" animation.
    if (self.mapItemList.count == 1) {
    MKMapItem *mapItem = [self.mapItemList objectAtIndex:0];

    self.title = mapItem.name;

    // Add the single annotation to our map.
    PlaceAnnotation *annotation = [[PlaceAnnotation alloc] init];
    annotation.coordinate = mapItem.placemark.location.coordinate;
    annotation.title = mapItem.name;
    annotation.url = mapItem.url;
    [self.mapView addAnnotation:annotation];

    // We have only one annotation, select it's callout.
    [self.mapView selectAnnotation:[self.mapView.annotations objectAtIndex:0] animated:YES];
    } else {
    self.title = @"All Places";

    // Add all the found annotations to the map.

    for (MKMapItem *item in self.mapItemList) {
    PlaceAnnotation *annotation = [[PlaceAnnotation alloc] init];
    annotation.coordinate = item.placemark.location.coordinate;
    annotation.title = item.name;
    annotation.url = item.url;
    [self.mapView addAnnotation:annotation];
    }
    }

    //10.
    - (void)mapViewDidFailLoadingMap:(MKMapView *)mapView withError:(NSError *)error {
    NSLog(@"Failed to load the map: %@", error);
    }

    - (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id <MKAnnotation>)annotation
    {
    MKPinAnnotationView *annotationView = nil;

    if ([annotation isKindOfClass:[PlaceAnnotation class]]) {
    annotationView = (MKPinAnnotationView *)[self.mapView dequeueReusableAnnotationViewWithIdentifier:@"Pin"];

    if (annotationView == nil) {
    annotationView = [[MKPinAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:@"Pin"];
    annotationView.canShowCallout = YES;
    annotationView.animatesDrop = YES;
    }
    }
    return annotationView;
    }

    //11. 界面将要消失时 removeAnnotations
    - (void)viewDidDisappear:(BOOL)animated {
    [super viewDidDisappear:animated];
    [self.mapView removeAnnotations:self.mapView.annotations];
    }

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  • 原文地址:https://www.cnblogs.com/levy/p/4800067.html
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