我想用 POST 方法发出请求,然后我希望他们返回 json 数据或NSDictionary,但他们只能在成功时返回字符串
像  NSString *response = [operation responseString];
任何人都知道如何让他们返回NSdictionary而不是NSString?
-(IBAction)SubmitLogin:(id)sender{
    NSLog(@"Login");
   // NSLog(@"%@",username);
    //START FUNGSI UNTUK POST, PUT, DELETE
    AFHTTPClient *httpClient = [[AFHTTPClient alloc] initWithBaseURL:signinUrl];
    [httpClient defaultValueForHeader:@"Accept"];
    NSDictionary *params = [NSDictionary dictionaryWithObjectsAndKeys:
                            @"someuser", @"username",
                            @"somepassword",@"password",
                            nil];
    NSMutableURLRequest *request = [httpClient requestWithMethod:@"POST"
                                                            path:@""
                                                      parameters:params];
 AFHTTPRequestOperation *operation = [[AFHTTPRequestOperation alloc] initWithRequest:request];
    [httpClient registerHTTPOperationClass:[AFHTTPRequestOperation class]];
    [operation setCompletionBlockWithSuccess:
     ^(AFHTTPRequestOperation *operation,
       id responseObject) {
         NSString *response = [operation responseString];
         NSLog(@"response: %@",response);
     } failure:^(AFHTTPRequestOperation *operation, NSError *error) {
         NSLog(@"error: %@", [operation error]);
     }];
    //call start on your request operation
    [operation start];