QFutureWatcher does not call a connected slot

Question

I have the following code that implements QtConcurrent::run()using QFutureWatcherto run a function fetch()that starts a shell process. Upon completion, I want to call the function writeDesc, but it is never called.

void MyClass::on_fetchButton_clicked()
{
    QFuture<void> fetcher;
    QFutureWatcher<void> watcher;
    connect(&watcher, SIGNAL(finished()), this, SLOT(writeDesc()));
    fetcher = QtConcurrent::run(this, &MyClass::fetch);
    watcher.setFuture(fetcher);
}

void MyClass::fetch()
{
    [...]
    qDebug()<<"Thread done";
}

void MyClass::writeDesc()
{
    qDebug()<<"Slot called";
    [...]
}

fetch()works fine, but the program only shows a debug message Thread done, not Slot called. Why not called writeDesc?

Answer 1

, MyClass::on_fetchButton_clicked(). - . . .