AFNetworking POST无法正常工作

Question

我正在尝试使用AFNetworking发出POST请求。我经历了SO，发现我需要包含 httpClient.parameterEncoding = AFJSONParameterEncoding

即使进行了更改，它仍然无效。我还缺少什么？这是代码

NSDictionary *subDictionaryUsers = [[NSDictionary alloc]initWithObjectsAndKeys:myObject.name,@"name",                                                     myObject.topic_description,@"description", nil];


    NSString *_restPath = [NSString stringWithFormat:@"spaces.json/auth_token=%@",myObject.auth_token];

    NSDictionary *params = [[NSDictionary alloc]initWithObjectsAndKeys:subDictionaryUsers,@"space",nil];

        myAppAFNClient *httpClient = [myAppAFNClient sharedClient];
    NSMutableURLRequest *request = [httpClient requestWithMethod:@"POST" path:_restPath parameters:params];

httpClient.parameterEncoding = AFJSONParameterEncoding;
    [httpClient getJsonResponse:request notificationString:@"add.hydramixer.topics"];

myAppAFNClient.m

-(void)getJsonResponse:(NSURLRequest *)_request notificationString:(NSString *)notifString{

    AFJSONRequestOperation *operation = [AFJSONRequestOperation JSONRequestOperationWithRequest:_request success:^(NSURLRequest *request, NSHTTPURLResponse *response, id JSON) {

        if([notifString length] != 0){
          // handling success
        }

    } failure:^(NSURLRequest *request, NSHTTPURLResponse *response, NSError *error, id JSON){
        // handling errors
    }];

    [operation start];
}