How I can close dialog, from another thread? Qt

I want to handle my button in this way:

1. Change text on label (somethink like "Please wait...")
2. Download some data from database
3. When downloading is done, close dialog where is this button.

When I do this:

void LoadingDialog::on_pushButton_clicked()
{
m_ui->labelStatus->setText("Pobieranie wysyłek...");

if(m_methodToDo == MethodToDo::LoadShipment)
{
    if(DataManager::getManager()->loadShipments())
    {
        this->close();
    }
}
}

the label hasn't changed text, is few second of lag (is downloading few k records) and dialog is closing.

When I try this:

void LoadingDialog::changeStatus(QString status)
{
m_ui->labelStatus->setText(status);
}

bool LoadingDialog::load()
{
if(m_methodToDo == MethodToDo::LoadShipment)
{
    if(DataManager::getManager()->loadShipments())
    {
        this->close();
    }
}
}

void LoadingDialog::on_pushButton_clicked()
{
QFuture<void> future3 = QtConcurrent::run([=]() {
    changeStatus("Pobieranie wysyłek..."); // "Downloading.."
});

QFuture<void> future = QtConcurrent::run([=]() {
    load();
});
}

the label has change text - it's ok is few second of lag - it's ok but dialog isn't closed, and my application throws exception :

Cannot send events to objects owned by a different thread. Current thread 229b1178. Receiver 'Dialog' (of type 'LoadingDialog') was created in thread 18b00590

Any suggestion?

First, changeStatus is not blocking, so do not run it on another thread. On the other hand if you want to invoking a slot from another thread you can use QMetaObject::invokeMethod():

bool LoadingDialog::load()
{
    if(m_methodToDo == MethodToDo::LoadShipment)
        if(DataManager::getManager()->loadShipments())
            QMetaObject::invokeMethod(this, "close", Qt::QueuedConnection);
}

void LoadingDialog::on_pushButton_clicked()
{
    changeStatus("Pobieranie wysyłek..."); // "Downloading.."

    QFuture<void> future = QtConcurrent::run([=]() {
        load();
    });
}