qt 之拖放操作-打印文档

{
    ui->setupUi(this);

    QAction *acton_print = new QAction("打印",this);
    QAction *acton_printPreview = new QAction("打印预览",this);
    QAction *acton_pdf = new QAction("生成pdf",this);

    connect(acton_print,&QAction::triggered,this,&MainWindow::doPrint);
    connect(acton_printPreview,&QAction::triggered,this,&MainWindow::doPrintPreview);
    connect(acton_pdf,&QAction::triggered,this,&MainWindow::createPdf);

    ui->mainToolBar->addAction(acton_print);
    ui->mainToolBar->addAction(acton_printPreview);
    ui->mainToolBar->addAction(acton_pdf);
}

MainWindow::~MainWindow()
{
    delete ui;
}

//打印
void MainWindow::doPrint()
{
    QPrinter printer;//创建打印机对象
    QPrintDialog dlg(&printer,this);//创建打印对话框
    //如果编辑器中有选中区域，则打印选中区域
    if(ui->textEdit->textCursor().hasSelection())
        dlg.addEnabledOption(QAbstractPrintDialog::PrintSelection);
    if(dlg.exec() == QDialog::Accepted)//如果对话框中按下打印按钮
        ui->textEdit->print(&printer);//则执行打印操作
}

//打印预览
void MainWindow::doPrintPreview()
{
    QPrinter printer;
    QPrintPreviewDialog preview(&printer,this);//创建打印预览对话框
    //当要生成预览页面时，发射paintRequested()信号
    connect(&preview,&QPrintPreviewDialog::paintRequested,this,&MainWindow::printPreview);
    preview.exec();
}

//预览页面的内容生成
void MainWindow::printPreview(QPrinter *printer)
{
    ui->textEdit->print(printer);//则执行打印操作
}

//生成pdf
void MainWindow::createPdf()
{
    QString fileName = QFileDialog::getSaveFileName(this,"导出PDF文件",QString(),"*.pdf");
    if(!fileName.isEmpty())
    {
        if(QFileInfo(fileName).suffix().isEmpty())
            fileName.append(".pdf");
        QPrinter printer;
        printer.setOutputFormat(QPrinter::PdfFormat);//指定输出格式为pdf
        printer.setOutputFileName(fileName);
        ui->textEdit->print(&printer);
    }
}