QNetworkReply не запускает

Я новичок в C ++ и Qt, поэтому, естественно, у меня проблемы. Я пытаюсь создать класс отдельно от MainWindow, который подключается к URL-адресу и получает ответ JSON. Однако после использования QObject :: connect программа не подключается к программе SLOT.

Вот мой код (jsonhandle.h):

#ifndef JSONHANDLE_H
#define JSONHANDLE_H

#include <string>
#include <QObject>
#include <QJsonObject>
#include <QtNetwork/QNetworkReply>

using std::string;

class jsonhandle: public QObject{
Q_OBJECT

public:
jsonhandle(string url);
void sendRequest();
void addArg(string name, string value);
void clearArg();
QJsonObject getResponse();

public slots:
void replyFinished(QNetworkReply * reply);

private:
////////////////////////////////////////////////////////////////////////////////////////////
bool gotResponse;                       //Determines whether or not a response was obtained.
string url;                             //The URL where the JSON request takes place.
int size;                               //The number of parameters.
string *param;                          //The array containing arguments.
int maxSize;                            //Keeps track of the top size of the array.
const int DEFAULT = 4;                  //The default value of the parameter array.
QJsonObject *response;                   //The object containing the JSON data.
////////////////////////////////////////////////////////////////////////////////////////////

void expandArray();                     //Expands the parameter array.
};

#endif // JSONHANDLE_H

jsonhandle.cpp:

#include "jsonhandle.h"#include <string>
#include <iostream>
#include <QJsonDocument>
#include <QJsonObject>
#include <QString>
#include <QUrl>
#include <QUrlQuery>
#include <QtNetwork/QNetworkAccessManager>
#include <QtNetwork/QNetworkReply>
#include <QtNetwork/QNetworkRequest>
#include <QDebug>

using std::string;

jsonhandle::jsonhandle(string url){
//Gets the url and argument list passed to the json handler.
this->url = url;
this->size = 0;
this->maxSize = DEFAULT;
this->gotResponse = false;
this->response = new QJsonObject();

//Now, creates the paramater array.
this->param = new string[DEFAULT];
}

void jsonhandle::addArg(string name, string value){
//Checks to see if the array is full.
if (size >= maxSize){
//The array has to be expanded.
expandArray();
}

//Now, inserts the name and parameter into param.
param[size++] = name;
param[size++] = value;
}

void jsonhandle::expandArray(){
//First gets the size of the array.
int newSize = (this->size) * 2;

//Creates a new array with double the size.
string *newArr = new string[newSize];

//Finally, populates the new array with the parameters.
std::copy(param, param + this-> size, newArr);

//Finally deletes the original param array.
delete[] param;
param = newArr;

//Finally, updates max count.
maxSize *= 2;
}

void jsonhandle::clearArg(){
//Clears the counters.
this->maxSize = DEFAULT;
this->size = 0;

//Deletes the param array off the stack.
delete[] this->param;
this->param = new string[DEFAULT];
}

void jsonhandle::sendRequest(){
//The network manager will post and recieve our HTTP requests.
QNetworkAccessManager *manager = new QNetworkAccessManager(this);

QObject::connect(manager, SIGNAL(finished(QNetworkReply *)), SLOT(replyFinished(QNetworkReply *)));

//The host of the webservice.
QString acceptedURL = QString::fromStdString(this->url);
QUrl url(acceptedURL);

//Sets up the post data request.
QNetworkRequest req;
req.setUrl(acceptedURL);
req.setHeader(QNetworkRequest::ContentTypeHeader, "application/x-www-form-urlencoded");

//Now, interacts with the data and gets all the additional parameters.
QUrlQuery query(url);
for (int i = 0; i < size; i += 2){
query.addQueryItem(QString::fromStdString(param[i]), QString::fromStdString(param[i + 1]));
}
url.setQuery(query);

//Update the request with the new query information.
req.setUrl(url);

// DEBUG TIP:
//   The following line will allow you print the full HTTP request that will be made
//   You can enter it directly into a browser, and the JSON object returned will be shown
//   This is why iostream is included in this file
std::cout<< url.toString().toStdString()<<std::endl;

//Post the request
manager->post(req, url.toEncoded());
}

void jsonhandle::replyFinished(QNetworkReply * reply){
if (reply->error() != QNetworkReply::NoError){
// A communication error has occurred
std::cout << "Error in connecting." << std::endl;
this->gotResponse = false;
}

//We read the JSON response into a QJsonObject
QJsonObject obj = QJsonDocument::fromJson(reply->readAll()).object();
this->response = &(obj);
this->gotResponse = true;
}

QJsonObject jsonhandle::getResponse(){
//Sees if a response was obtained from JSON
if (gotResponse == false){
response->insert("error",QJsonValue::Null);
}

return *response;
}

Дайте мне знать, если вы, ребята, что-нибудь придумаете.