iOS JSON数组和MapKit

我正在尝试使用MapKit映射JSON数组。 我可以使用下面的代码在地图上得到一个点，但是我需要标记几十个引脚，并且我准备了一个JSON数组。 我的单点代码如下。

在我的.h文件中：

#import  #import  @interface MapViewController : UIViewController { MKMapView *mapView; NSData *data; } @property (nonatomic, retain) IBOutlet MKMapView *mapView; @end 

在我的.m文件中：

 NSData *data = @"[{"id":"1","name":"Jiffy Lube","lat":"21.306","lon":"-157.861"}, {"id":"2","name":"Bills Oil","lat":"21.301","lon":"-157.863"},{"id":"3","name":"Auto Zone","lat":"21.307","lon":"- 157.862"}]"; // parse the JSON into a NSArray NSError *error; NSArray *array = [NSJSONSerialization JSONObjectWithData:data options:0 error:&error]; 

Answer 1

您的JSON是一个字典项数组。 因此，您可以通过NSJSONSerialization检索完整数组，然后遍历生成的数组中的字典条目。

首先，你最初说你有JSON，如下所示：

 [{"id":"1","name":"Jiffy Lube","lat":"21.306","lon":"-157.861"}, {"id":"2","name":"Bills Oil","lat":"21.301","lon":"-157.863"}, {"id":"3","name":"Auto Zone","lat":"21.307","lon":"-157.862"}] 

因此，如果它位于您已包含在捆绑包中的文件“test.json”中，则可以将其加载为：

 // load the data from local file NSString *path = [[NSBundle mainBundle] pathForResource:@"test" ofType:@"json"]; NSData *data = [NSData dataWithContentsOfFile:path]; 

如果你在Web服务器上有这个，你可以像这样检索它：

 // load the data from web server NSURL *url = [NSURL URLWithString:@"http://insert.your.server/and/url/here/test.json"]; NSURLRequest *request = [NSURLRequest requestWithURL:url]; [NSURLConnection sendAsynchronousRequest:request queue:[NSOperationQueue mainQueue] completionHandler:^(NSURLResponse *response, NSData *data, NSError *connectionError) { // use NSData here }]; 

假设您将JSON提要加载到名为data的NSData对象中，您可以执行以下操作：

 // parse the JSON into a NSArray NSError *error; NSArray *array = [NSJSONSerialization JSONObjectWithData:data options:0 error:&error]; if (error != nil) { // handle the error as you want } // a few variables to be used as we iterate through the array of results CLLocationCoordinate2D location; // coordinates of the annotation NSMutableArray *newAnnotations = [NSMutableArray array]; // an array in which we'll save our annotations temporarily MKPointAnnotation *newAnnotation; // the pointer to the annotation we're adding // iterate through the array, adding an annotation to our our array of new annotations for (NSDictionary *dictionary in array) { // retrieve latitude and longitude from the dictionary entry location.latitude = [dictionary[@"lat"] doubleValue]; location.longitude = [dictionary[@"lon"] doubleValue]; // create the annotation newAnnotation = [[MKPointAnnotation alloc] init]; newAnnotation.title = dictionary[@"name"]; newAnnotation.coordinate = location; // add it to our array // // incidentally, generally I just add it to the mapview directly, but // given that you have a didAddAnnotationViews, we'll just build up // an array and add them all to the map view in one step after we're // done iterating through the JSON results [newAnnotations addObject:newAnnotation]; // clean up [newAnnotation release]; } // when done, add the annotations [self.mapView addAnnotations:newAnnotations];