QT5编译使用QFtp的方法步骤

CONFIG(debug, debug|release) {
  LIBS += -lQt5Ftpd
} else {
  LIBS += -lQt5Ftp
}

 progressDialog = new QProgressDialog("download...", nullptr, 0, 100, this);
 progressDialog->setWindowModality(Qt::WindowModal);
 auto winFlags = windowFlags() & ~Qt::WindowMinMaxButtonsHint;
 progressDialog->setWindowFlags(winFlags &~ Qt::WindowCloseButtonHint); //去掉窗口的默认按钮
 progressDialog->reset();          //避免提前显示
 progressDialog->setAutoClose(false);
 progressDialog->setAutoReset(false);

//connect(progressDialog, SIGNAL(canceled()), this, SLOT(cancelDownload()));

fileList->setSelectionMode(QAbstractItemView::ExtendedSelection);

QList<QTreeWidgetItem*> selectedItemList = fileList->selectedItems();
for (int i = 0; i < selectedItemList.size(); i++)
 {
  QString fileName = selectedItemList[i]->text(0);
  if (QFile::exists(fileName)) {
    QMessageBox::information(this, tr("FTP"),
    tr("There already exists a file called %1 in the current directory.").arg(fileName));
    return;
  }
  file = new QFile(fileName);
  if (!file->open(QIODevice::WriteOnly)) {
    QMessageBox::information(this, tr("FTP"),
    tr("Unable to save the file %1: %2.").arg(fileName).arg(file->errorString()));
    delete file;
    return;
  }
  ftp->get(fileName, file);
  progressDialog->setLabelText(tr("Downloading %1...").arg(fileName));
  downloadButton->setEnabled(false);
  progressDialog->exec();
}

git clone https://github.com/zhoutk/qtDemo
cd qtDemo/qftp & mkdir build & cd build
cmake ..
cmake --build .