void ArialPrintTest::printSlot()
{
    // 创建打印机对象
    QPrinter printer(QPrinter::ScreenResolution);
    // 创建打印对话框
    QString printerName = printer.printerName();
    if (printerName.size() == 0)
        return;
    QPrintDialog dlg(&printer, this);
    // 如果在对话框中按下了打印按钮，则执行打印操作
    if (dlg.exec() == QDialog::Accepted)
    {
        QPainter painter;
        bool bOk = painter.begin(&printer);
        if (bOk)
        {
            paintText(&painter);
        }
    }
}

void ArialPrintTest::paintText(QPainter *painter)
{
    QFont font;
    font.setPointSize(8);
    font.setFamily("Arial");
    font.setKerning(false);

    QTextOption textOption;
    textOption.setWrapMode(QTextOption::WrapAtWordBoundaryOrAnywhere);
    textOption.setAlignment(Qt::AlignJustify);
    QString strText = "Element A QTextDocument can be used ,to present formatted text A QTextDocument can be used to present formatted text";

    QTextLayout *pTextLayout = new QTextLayout();
    pTextLayout->setText(strText);
    pTextLayout->setTextOption(textOption);
    pTextLayout->setFont(font);
    double height = 0;

    int lineWidth = 348;
    int lineSpacing = 1;
    if (!pTextLayout->text().isEmpty())
    {
        pTextLayout->beginLayout();
        while (true)
        {
            QTextLine line = pTextLayout->createLine();
            if (!line.isValid())
                break;
            line.setLineWidth(lineWidth);
            line.setPosition(QPointF(0, height));
            height += line.height();
            height += lineSpacing;
        }
        pTextLayout->endLayout();
    }
    QRect textRect(50, 50, 348, 75);
    pTextLayout->draw(painter, textRect.topLeft(), QVector<QTextLayout::FormatRange>(), textRect);
    painter->end();
}