Question

我正在尝试使用NSURLSessions中的Objective C获取JSON数据。我可以获取数据，但我无法将其保存到数组中以用作另一个tableview的数据源。我不确定发生了什么，我对Sessions不熟悉。此外，当我在完成块内部使用for循环时，我得到一个无限循环的Stop对象。我想使用NSURLSession，所以我也可以缓存数据，因为这些数据几乎没有变化，但可能每个月左右一次。我的代码如下。

-(NSMutableArray *)fetchStopListing {

NSURL *url = [NSURL URLWithString:[NSString stringWithFormat:@"%@%@",kStopList, kApiKey]];
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];


NSURLSession *session = [NSURLSession sessionWithConfiguration:[NSURLSessionConfiguration defaultSessionConfiguration]];



[[session dataTaskWithRequest:request
 completionHandler:^(NSData * data, NSURLResponse * response, NSError * error) {
     if (!data) {
         NSLog(@"Download Error: %@", error.localizedDescription);

         //Create a UIAlertController
         UIAlertController *alert = [UIAlertController alertControllerWithTitle:@"Error" message:[NSString stringWithFormat:@"Error %@", error.localizedDescription] preferredStyle:UIAlertControllerStyleAlert];

         //Create a UIAlerAction that can be added to the alert
         UIAlertAction *ok = [UIAlertAction actionWithTitle:@"Ok" style:UIAlertActionStyleDefault handler:nil];

         //Add UIAlertAction ok to UIAlertController
         [alert addAction:ok];
     } else {

         NSDictionary *JSON = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingMutableContainers error:&error];

         NSArray *JSONArray = [JSON valueForKeyPath:@"stops.stop"];
         //NSLog(@"Hey this is JSON Data %@", JSON);

         self.stopsArray = [NSMutableArray new];

         for (int i = 0; i < [JSONArray count] ;i++) {
             float lat = [[JSONArray[i] objectForKey:@"stoplat"] floatValue];

             float lng = [[JSONArray[i] objectForKey:@"stoplng"] floatValue];
             NSString *stopNumber = [JSONArray[i] objectForKey:@"stopnumber"];
             NSString *stoptitle = [JSONArray[i] objectForKey:@"stoptitle"];
             Stops *newStop = [[Stops alloc] initWithStopLat:lat stopLong:lng stopNumber:stopNumber stopTitle:stoptitle];
             //NSLog(@"This is th newStop: %@", newStop.stopTitle);
             [self.stopsArray addObject:newStop];

             for (Stops *stop in self.stopsArray) {
                 NSLog(@"Stoptitle: %@",stop.stopTitle);

             }

         }


     }
 }] resume];



  NSLog(@"is this getting called");

  //NSLog(@"%@",self.stopsArray[5]);



  return self.stopsArray;
}

使用NSURLSessions获取JSON数据目标C.

0 个答案: