前言

本文分享QT开发PDF阅读器技术，希望对各位小伙伴有所帮助！

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结果展示：

我将收获到的：

1. 如何创建PDFViewer

2.创建PDFViewer所依赖的QT库

3.PDFViewer的用处

前言

1.准备PDFViewer所依赖的库

2.创建PDF Viewer

小结：

1.准备PDFViewer所依赖的库

》使用开发的QT版本：5.15.2

》存在问题：不能直接添加PDF模块

》原因：QT5.15.2版本已带有pdf模块，但并未在include中包含，但是在lib和bin目录下能找到相应的.lib和.dll文件。

》解决方案：

》下载QT5.15.2源码

》将“Qt\5.15.2\Src\qtwebengine\include”文件夹下的QtPdf和QtPdfWidgets复制到“Qt\5.15.2\msvc2019_64\include”文件夹下。

》将“Qt\5.15.2\Src\qtwebengine\src\pdf\api”文件夹下的.h文件复制到“Qt\5.15.2\msvc2019_64\include\QtPdf”文件夹下。

》将“Qt\5.15.2\Src\qtwebengine\src\pdfwidgets”文件夹下的.h文件复制到“Qt\5.15.2\msvc2019_64\include\QtPdfWidgets”文件夹下

》我已将QtPdf整理成单独的依赖库，需要的小伙伴可以联系我下载。

也上传CSDN，下载地址：QT开发PDF阅读器，代码简洁易用！资源-CSDN文库

2.创建PDF Viewer

》创建UI文件

》核心为PageSelector(页面选择)和ZoomSelector（缩放）

》下载地址：QT开发PDF阅读器，代码简洁易用！资源-CSDN文库

》代码如下：

PageSelector.h文件

#ifndef PAGESELECTOR_H
#define PAGESELECTOR_H#include <QWidget>class QLabel;
class QLineEdit;
class QPdfDocument;
class QPdfPageNavigation;
class QToolButton;class PageSelector : public QWidget
{Q_OBJECTpublic:explicit PageSelector(QWidget *parent = nullptr);void setPageNavigation(QPdfPageNavigation *pageNavigation);private slots:void onCurrentPageChanged(int page);void pageNumberEdited();private:QPdfPageNavigation *m_pageNavigation;QLineEdit *m_pageNumberEdit;QLabel *m_pageCountLabel;QToolButton *m_previousPageButton;QToolButton *m_nextPageButton;
};#endif // PAGESELECTOR_H

PageSelector.cpp文件

#include "pageselector.h"#include <QHBoxLayout>
#include <QLabel>
#include <QLineEdit>
#include <QPdfPageNavigation>
#include <QToolButton>PageSelector::PageSelector(QWidget *parent): QWidget(parent), m_pageNavigation(nullptr)
{QHBoxLayout *layout = new QHBoxLayout(this);m_previousPageButton = new QToolButton(this);m_previousPageButton->setText("<");m_previousPageButton->setEnabled(false);m_pageNumberEdit = new QLineEdit(this);m_pageNumberEdit->setAlignment(Qt::AlignRight);m_pageCountLabel = new QLabel(this);m_pageCountLabel->setText("0");m_nextPageButton = new QToolButton(this);m_nextPageButton->setText(">");m_nextPageButton->setEnabled(false);layout->addWidget(m_previousPageButton);layout->addWidget(m_pageNumberEdit);layout->addWidget(m_pageCountLabel);layout->addWidget(m_nextPageButton);
}void PageSelector::setPageNavigation(QPdfPageNavigation *pageNavigation)
{m_pageNavigation = pageNavigation;connect(m_previousPageButton, &QToolButton::clicked, m_pageNavigation, &QPdfPageNavigation::goToPreviousPage);connect(m_pageNavigation, &QPdfPageNavigation::canGoToPreviousPageChanged, m_previousPageButton, &QToolButton::setEnabled);connect(m_pageNavigation, &QPdfPageNavigation::currentPageChanged, this, &PageSelector::onCurrentPageChanged);connect(m_pageNavigation, &QPdfPageNavigation::pageCountChanged, this, [this](int pageCount){ m_pageCountLabel->setText(QString::fromLatin1("/ %1").arg(pageCount)); });connect(m_pageNumberEdit, &QLineEdit::editingFinished, this, &PageSelector::pageNumberEdited);connect(m_nextPageButton, &QToolButton::clicked, m_pageNavigation, &QPdfPageNavigation::goToNextPage);connect(m_pageNavigation, &QPdfPageNavigation::canGoToNextPageChanged, m_nextPageButton, &QToolButton::setEnabled);onCurrentPageChanged(m_pageNavigation->currentPage());
}void PageSelector::onCurrentPageChanged(int page)
{if (m_pageNavigation->pageCount() == 0)m_pageNumberEdit->setText(QString::number(0));elsem_pageNumberEdit->setText(QString::number(page + 1));
}void PageSelector::pageNumberEdited()
{if (!m_pageNavigation)return;const QString text = m_pageNumberEdit->text();bool ok = false;const int pageNumber = text.toInt(&ok);if (!ok)onCurrentPageChanged(m_pageNavigation->currentPage());elsem_pageNavigation->setCurrentPage(qBound(0, pageNumber - 1, m_pageNavigation->pageCount() - 1));
}

ZoomSelector.h文件

#ifndef ZOOMSELECTOR_H
#define ZOOMSELECTOR_H#include <QComboBox>
#include <QPdfView>class ZoomSelector : public QComboBox
{Q_OBJECTpublic:explicit ZoomSelector(QWidget *parent = nullptr);public slots:void setZoomFactor(qreal zoomFactor);void reset();signals:void zoomModeChanged(QPdfView::ZoomMode zoomMode);void zoomFactorChanged(qreal zoomFactor);private slots:void onCurrentTextChanged(const QString &text);
};#endif // ZOOMSELECTOR_H

ZoomSelector.cpp文件

#include "zoomselector.h"#include <QLineEdit>ZoomSelector::ZoomSelector(QWidget* parent): QComboBox(parent)
{setEditable(true);addItem(QLatin1String("Fit Width"));addItem(QLatin1String("Fit Page"));addItem(QLatin1String("12%"));addItem(QLatin1String("25%"));addItem(QLatin1String("33%"));addItem(QLatin1String("50%"));addItem(QLatin1String("66%"));addItem(QLatin1String("75%"));addItem(QLatin1String("100%"));addItem(QLatin1String("125%"));addItem(QLatin1String("150%"));addItem(QLatin1String("200%"));addItem(QLatin1String("400%"));connect(this, static_cast<void(QComboBox::*)(const QString&)>(&QComboBox::currentIndexChanged),this, &ZoomSelector::onCurrentTextChanged);connect(lineEdit(), &QLineEdit::editingFinished,this, [this]() {onCurrentTextChanged(lineEdit()->text()); });
}void ZoomSelector::setZoomFactor(qreal zoomFactor)
{setCurrentText(QString::number(qRound(zoomFactor * 100)) + QLatin1String("%"));
}void ZoomSelector::reset()
{setCurrentIndex(8); // 100%
}void ZoomSelector::onCurrentTextChanged(const QString& text)
{if (text == QLatin1String("Fit Width")) {emit zoomModeChanged(QPdfView::FitToWidth);}else if (text == QLatin1String("Fit Page")) {emit zoomModeChanged(QPdfView::FitInView);}else {qreal factor = 1.0;QString withoutPercent(text);withoutPercent.remove(QLatin1Char('%'));bool ok = false;const int zoomLevel = withoutPercent.toInt(&ok);if (ok)factor = zoomLevel / 100.0;emit zoomModeChanged(QPdfView::CustomZoom);emit zoomFactorChanged(factor);}
}