Сигналы и слоты

MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent)
    , ui(new Ui::MainWindow)
{
    ui->setupUi(this);
    ui->ButtonOK->setDefault(true);
    connect(ui->ButtonOK ,SIGNAL(clicked(bool)),this,SLOT(on_pushButton_clicked()));
}
 
MainWindow::~MainWindow()
{
    delete ui;
}
void MainWindow::on_pushButton_clicked()
{
    QString emitent = ui->ticker->text();//берем введенный тикер и ищем
на это получаю это: QMetaObject::connectSlotsByName: No matching signal for on_pushButton_clicked()
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HttpFetcher::HttpFetcher(QObject *parent) : QObject(parent)
{
    manager = new QNetworkAccessManager;
    connect(manager,SIGNAL(finished(QNetworkReply*)), this, SLOT(Result));
}
//Принимаем url получаем результат
void HttpFetcher::Result(const QUrl &url)
{  
    reply = manager->get(QNetworkRequest(QUrl(url)));
    //reply->ignoreSslErrors();
    if(reply->error() == QNetworkReply::NoError)
    {
        //PREVPRICE = xmlParser(reply->readAll());
        QString str = QString::fromUtf8(reply->readAll().data(),reply->readAll().size());
        int statuscode = reply->attribute(QNetworkRequest::HttpStatusCodeAttribute).toInt();
        qDebug()<<QVariant(statuscode).toString();
        qDebug() << reply->readAll();
    }
    else
    {
        qDebug()<<"Ошибка:"<<reply->errorString();
        qWarning() << "Ошибка HTTP:" << reply->errorString();
        QCoreApplication::quit();
    }
    reply->deleteLater();
    manager->deleteLater();
}