IOS/AFNetworking：排隊兩個JSON操作，然後比較返回的NSArrays

Question

對於我的應用程序，我必須連接到兩個返回JSON的webservices。

我第一次使用GCD推出自己的網絡代碼，但看到AFNetworking如何處理事情，我決定實現它。大部分事情都沒有問題，但是在某些時候我正在檢索兩個充滿對象的數組。這兩個數組然後使用不同的方法進行比較。不知怎的，實際的排隊是延遲或不工作，這取決於我使用的代碼。

使用：

NSArray *operations = [NSArray arrayWithObjects:operation, operation1, nil]; 
     AFHTTPClient *client = [[AFHTTPClient alloc]init]; 

     [client enqueueBatchOfHTTPRequestOperations:operations progressBlock:nil completionBlock:^(NSArray *operations) { 
      [self compareArrays:self]; 
     } 

它只是掛起。

當使用：

[operation start]; 
    [operation1 start]; 
    [operation waitUntilFinished]; 
    [operation1 waitUntilFinished]; 

    [self compareArrays:self]; 

在端，它得到的陣列，但只有UI已經形成之後進行比較。

編輯： 我檢查了戴夫的答案，它看起來非常精簡。 我的應用會受益於使用AFHTTPClient，還是這種方法（使用AFJSONRequestOperation）提供相同的功能？我記得AFHTTPClient現在自己處理可達性（儘管你需要設置它）。我擺弄了一下週圍，並得到了這個工作：

NSOperationQueue *queue = [[NSOperationQueue alloc]init]; 
    WebServiceStore *wss = [WebServiceStore sharedWebServiceStore]; 
    self.userData = wss.userData; 
    serviceURL = [NSString stringWithFormat: @"WEBSERVICE URL"]; 
    NSString* zoekFruit = [NSString stringWithFormat: 
          @"%@?customer=%@&gebruiker=%@&password=%@&breedte=%@&hoogte=%@&diameter=%@", 
          serviceURL, 
          self.userData.Klant, 
          self.userData.Gebruiker, 
          self.userData.Wachtwoord, 
          breedte, 
          hoogte, 
          diameter]; 

    NSURL *url = [NSURL URLWithString:[zoekFruit stringByAddingPercentEscapesUsingEncoding: NSUTF8StringEncoding]]; 

     NSURLRequest *request = [NSURLRequest requestWithURL:url]; 

     AFJSONRequestOperation *operation = [AFJSONRequestOperation JSONRequestOperationWithRequest:request success:^(NSURLRequest *request, NSHTTPURLResponse *response, id JSON) { 
      id results = [JSON valueForKey:@"data"]; 

      [results enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) { 

       //Initiate the BWBand 

       BWBand *band = [[BWBand alloc]init]; 

       //Set the BWBand's properties with valueforKey (or so).      

       [getBandenArray addObject:band]; 
      }]; 

      NSLog(@"getBandenArray: %@",getBandenArray); 

     } failure:^(NSURLRequest *request, NSHTTPURLResponse *response, NSError *error, id JSON) { 
      UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Error" message:@"Error retrieving Banden" delegate:self cancelButtonTitle:@"Cancel" otherButtonTitles:@"Ok", nil]; 
      [alert show]; 
     }]; 

     [queue addOperation:operation]; 

Answer 1

的AFNetworking類將允許您創建了一堆作業，然後把他們全部關閉，以進行處理。您爲每個單獨請求的成功/失敗和/或所有請求處理完畢後添加一些代碼。

下面是你可能做什麼的概述。我會將細節，實際比較以及錯誤處理留給您的想象。 :)

-(void)fetchAllTheData { 
    NSMutableArray * operations = [NSMutableArray array]; 
    for (NSString * url in self.urlsToFetchArray) { 
     [operations addObject:[self operationToFetchSomeJSON:url]]; 
    } 
    AFHTTPClient *client = [AFHTTPClient clientWithBaseURL:[NSURL URLWithString:[PREFS objectForKey:@"categoryUrlBase"]]]; 
    [client enqueueBatchOfHTTPRequestOperations:operations 
            progressBlock:^(NSUInteger numberOfFinishedOperations, NSUInteger totalNumberOfOperations) { 
             NSLog(@"Finished %d of %d", numberOfFinishedOperations, totalNumberOfOperations); 
            } 
           completionBlock:^(NSArray *operations) { 
            DLog(@"All operations finished"); 
            [[NSNotificationCenter defaultCenter] postNotificationName:@"Compare Everything" object:nil]; 
           }]; 
} 

-(AFHTTPRequestOperation *)operationToFetchSomeJSON:(NSString*)whichOne { 
    NSURL * jsonURL = [NSURL URLWithString:whichOne]; 
    NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:jsonURL]; 
    [request setHTTPShouldHandleCookies:NO]; 
    [request addValue:@"application/json" forHTTPHeaderField:@"Accept"]; 

    AFHTTPRequestOperation *operation = [[AFHTTPRequestOperation alloc] initWithRequest:request]; 
    [operation setCompletionBlockWithSuccess:^(AFHTTPRequestOperation *operation, id responseObject) { 
     NSLog(@"My data = %@", operation.responseString); // or responseData 
     // Got the data; save it off. 
    } failure:^(AFHTTPRequestOperation *operation, NSError *error) { 
     DLog(@"Error downloading: %@ %@", whichOne, error); 
    }]; 
    return operation; 
} 

希望有所幫助。