Question

我正在关注本教程：http://www.raywenderlich.com/13160/using-the-google-places-api-with-mapkit，但出于某种原因我的应用程序正在返回：

Google数据:( ）

这是我的.h文件：

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

#define kBgQueue dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0)

#define kGOOGLE_API_KEY @"API PLACED HERE, LEFT BLANK FOR STACKOVERFLOW"

@interface ViewController : UIViewController <MKMapViewDelegate,     CLLocationManagerDelegate>
{
CLLocationManager *locationManager;
CLLocationCoordinate2D currentCentre;
int currenDist;
}

@property (strong, nonatomic) IBOutlet MKMapView *mapView;
@end

和我的实施文件：

#import "ViewController.h"

@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad
{
[super viewDidLoad];

// Do any additional setup after loading the view, typically from a nib.

//Make this controller the delegate for the map view.
self.mapView.delegate = self;

// Ensure that you can view your own location in the map view.
[self.mapView setShowsUserLocation:YES];

//Instantiate a location object.
locationManager = [[CLLocationManager alloc] init];

//Make this controller the delegate for the location manager.
[locationManager setDelegate:self];

//Set some parameters for the location object.
[locationManager setDistanceFilter:kCLDistanceFilterNone];
[locationManager setDesiredAccuracy:kCLLocationAccuracyBest];
}

- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
- (IBAction)toolBarButtonPress:(UIBarButtonItem *)sender {
UIBarButtonItem *button = (UIBarButtonItem *)sender;
NSString *buttonTitle = [button.title lowercaseString];
[self queryGooglePlaces:buttonTitle];

}

-(void) queryGooglePlaces: (NSString *) googleType {
NSString *url = [NSString     stringWithFormat:@"https://maps.googleapis.com/maps/api/place/search/json?  location=%f,%f&radius=%@&types=%@&sensor=true&key=%@", currentCentre.latitude, currentCentre.longitude, [NSString stringWithFormat:@"%i", currenDist], googleType,     kGOOGLE_API_KEY];
url = [url stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];

NSLog(@"%@", url);

//Formulate the string as a URL object.
NSURL *googleRequestURL=[NSURL URLWithString:url];

// Retrieve the results of the URL.
dispatch_async(kBgQueue, ^{
    NSData* data = [NSData dataWithContentsOfURL: googleRequestURL];
    [self performSelectorOnMainThread:@selector(fetchedData:) withObject:data  waitUntilDone:YES];
});
}

-(void)fetchedData:(NSData *)responseData {
//parse out the json data
NSError* error;
NSDictionary* json = [NSJSONSerialization
                      JSONObjectWithData:responseData

                      options:kNilOptions
                      error:&error];

//The results from Google will be an array obtained from the NSDictionary object with the  key "results".
NSArray* places = [json objectForKey:@"results"];

//Write out the data to the console.
NSLog(@"Google Data: %@", places);
}

-(void)mapView:(MKMapView *)mapView regionDidChangeAnimated:(BOOL)animated {
//Get the east and west points on the map so you can calculate the distance (zoom level)  of the current map view.
MKMapRect mRect = self.mapView.visibleMapRect;
MKMapPoint eastMapPoint = MKMapPointMake(MKMapRectGetMinX(mRect),  MKMapRectGetMidY(mRect));
MKMapPoint westMapPoint = MKMapPointMake(MKMapRectGetMaxX(mRect), MKMapRectGetMidY(mRect));

//Set your current distance instance variable.
currenDist = MKMetersBetweenMapPoints(eastMapPoint, westMapPoint);

//Set your current center point on the map instance variable.
currentCentre = self.mapView.centerCoordinate;
}

#pragma mark - MKMapViewDelegate methods.
- (void)mapView:(MKMapView *)mv didAddAnnotationViews:(NSArray *)views {
MKCoordinateRegion region;
region =  MKCoordinateRegionMakeWithDistance(locationManager.location.coordinate,1000,1000);


[mv setRegion:region animated:YES];
}

@end

我最终格式化网址的控制台日志是：

https://maps.googleapis.com/maps/api/place/search/json? location=HIDDENLAT,HIDDENLONG&radius=995&types=bar&sensor=true&key=HIDDENAPI

我已经替换了上面生成的lat，long和API值，但它们是作为正确的值返回的吗？

我发现另一个SO答案说要添加：

url = [url stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];

我做了但这对我不起作用？

为什么这不起作用的任何想法！？我拉着我的头发试图把它拉出来！

谢谢！

Answer 1

对于未来的求职者，这可能是一些问题，包括您的API密钥，搜索半径，搜索＆＃34;类型＆＃34;或JSON解析问题。但是，代码应该与Gary Stewart在上面发布的完全相同。他甚至只是通过提问来帮我找到答案......

在queryGooglePlaces方法中的URL字符串之后添加NSLog(@"%@", url);，如上所述。这会将URL请求记录到您的控制台，以便您可以确保按预期编译它。如果是，但您仍然无法获取数据，则复制您从控制台生成的URL并在Web浏览器中打开它。在生成页面的底部，它会告诉您为什么没有获取数据。

来自Google的开发人员文档：

＆＃34;状态＆＃34;搜索响应对象中的字段包含   请求的状态，并可能包含调试信息以提供帮助   您追踪请求失败的原因。＆＃34;状态＆＃34;字段可能包含   以下值：

确定表示没有发生错误;这个地方成功了   检测到并且至少返回了一个结果。 ZERO_RESULTS 表示   搜索成功但没有返回任何结果。这可能发生   如果搜索在远程位置传递了一个latlng。    OVER_QUERY_LIMIT 表示您已超过配额。    REQUEST_DENIED 表示您的请求通常被拒绝   因为缺乏传感器参数。一般来说， INVALID_REQUEST   表示所需的查询参数（位置或半径）   丢失。

我的问题是我正在发送搜索＆＃34;输入＆＃34; ＆＃34;早餐＆＃34;而不是简单的＆＃34;食物＆＃34;。傻我，＆＃34;早餐＆＃34;将是一个关键字，而不是一个类型。

（顺便说一句，这里是支持的类型列表：https://developers.google.com/places/documentation/supported_types）

希望这有助于发现您的问题。祝你好运！

Answer 2

更改

@"https://maps.googleapis.com/maps/api/place/search/json?  location=%f,%f&radius=%@&types=%@&sensor=true&key=%@"

到

@"https://maps.googleapis.com/maps/api/place/search/json?location=%f,%f&radius=%@&types=%@&sensor=true&key=%@"

（即，在url模板字符串中的？之后没有空格）

Google Places API没有返回任何结果？

2 个答案: