PDF 查看器 Widget 範例

基於 Widget 的 PDF 查看器允許捲動瀏覽頁麵。

PDF Viewer 演示如何使用 QPdfView class to render PDF documents and the QPdfPageNavigator class to navigate them.

Qt Creator and the integrated Qt Widgets Designer were used to create the example UI and to connect it to the code. This affects the code, which might be somewhat different to what you would typically write by hand. For more information about using Qt Widgets Designer, see Qt Widgets Designer 手冊 and Qt Creator 教程: Qt Widgets 應用程序 .

運行範例

要運行範例從 Qt Creator ，打開歡迎模式，然後選擇範例從範例。更多信息，見 Qt Creator：教程：構建並運行 .

創建主窗口

The MainWindow class inherits the QMainWindow 類：

class MainWindow : public QMainWindow
{
    Q_OBJECT
public:
    explicit MainWindow(QWidget *parent = nullptr);
    ~MainWindow();

類聲明匹配選擇器動作的公共和私有槽：

public slots:
    void open(const QUrl &docLocation);
private slots:
    void bookmarkSelected(const QModelIndex &index);
    void pageSelected(int page);
    void searchResultSelected(const QModelIndex &current, const QModelIndex &previous);
    // action handlers
    void on_actionOpen_triggered();
    void on_actionQuit_triggered();
    void on_actionAbout_triggered();
    void on_actionAbout_Qt_triggered();
    void on_actionZoom_In_triggered();
    void on_actionZoom_Out_triggered();
    void on_actionPrevious_Page_triggered();
    void on_actionNext_Page_triggered();
    void on_thumbnailsView_activated(const QModelIndex &index);
    void on_actionContinuous_triggered();
    void on_actionBack_triggered();
    void on_actionForward_triggered();

The actual layout of the main window is specified in a .ui file. The widgets and actions are available at runtime in the ui member variable.

    void on_actionFindNext_triggered();
    void on_actionFindPrevious_triggered();
private:
    Ui::MainWindow *ui;

The m_zoomSelector variable holds the zoom selector and the m_pageSelector holds the page selector. The m_document variable is an instance of the QPdfDocument class that contains the PDF document.

    ZoomSelector *m_zoomSelector;
    QPdfPageSelector *m_pageSelector;
    QPdfSearchModel *m_searchModel;
    QLineEdit *m_searchField;
    QFileDialog *m_fileDialog = nullptr;
    QPdfDocument *m_document;
};

The actual setup of the different objects is done in the MainWindow constructor:

MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent)
    , ui(new Ui::MainWindow)
    , m_zoomSelector(new ZoomSelector(this))
    , m_pageSelector(new QPdfPageSelector(this))
    , m_searchModel(new QPdfSearchModel(this))
    , m_searchField(new QLineEdit(this))
    , m_document(new QPdfDocument(this))
{

構造函數首先調用 setupUi() to construct most of the main window according to the UI file. The zoom and page selectors need to be added to the toolbar via QToolBar::insertWidget (), because that cannot be done in a UI file:

    ui->setupUi(this);
    m_zoomSelector->setMaximumWidth(150);
    ui->mainToolBar->insertWidget(ui->actionZoom_In, m_zoomSelector);
    ui->mainToolBar->insertWidget(ui->actionForward, m_pageSelector);

We connect relevant signals to the page selector spinbox and the browser-style back and forward buttons:

    connect(m_pageSelector, &QPdfPageSelector::currentPageChanged, this, &MainWindow::pageSelected);
    m_pageSelector->setDocument(m_document);
    auto nav = ui->pdfView->pageNavigator();
    connect(nav, &QPdfPageNavigator::currentPageChanged, m_pageSelector, &QPdfPageSelector::setCurrentPage);
    connect(nav, &QPdfPageNavigator::backAvailableChanged, ui->actionBack, &QAction::setEnabled);
    connect(nav, &QPdfPageNavigator::forwardAvailableChanged, ui->actionForward, &QAction::setEnabled);

連接 zoomModeChanged and zoomFactor changed signals of the PDF view to the functions that reset the zoom selector:

    connect(m_zoomSelector, &ZoomSelector::zoomModeChanged, ui->pdfView, &QPdfView::setZoomMode);
    connect(m_zoomSelector, &ZoomSelector::zoomFactorChanged, ui->pdfView, &QPdfView::setZoomFactor);
    m_zoomSelector->reset();

We then load the PDF document to the viewer:

    ...
    ui->pdfView->setSearchModel(m_searchModel);

Finally, we connect the zoomFactorChanged signal to the function that sets the value of the zoom selector:

    ui->searchToolBar->insertWidget(ui->actionFindPrevious, m_searchField);
    connect(new QShortcut(QKeySequence::Find, this), &QShortcut::activated, this, [this]() {
        m_searchField->setFocus(Qt::ShortcutFocusReason);
    });

文件和歸屬

範例工程 @ code.qt.io