feat: v0.6.0 —— 选中语言（中/英）即时切换，导出不再有预览窗口

导出
- 去掉导出预览对话框：Ctrl+E 直接弹保存对话框，选路径即导出
- 导出失败才弹提示，成功只在状态栏显示一行

多语言
- 新增 LanguageManager：中文（zh_CN）/ 英文（en），视图 → 语言 切换，
  立即生效并记住选择
- 英文翻译由 translations/voiletmark_en.ts（69 条）编译成 .qm 内嵌
- 打包 Qt 官方的 qtbase_zh_CN.qm，文件对话框 / 消息框的按钮也跟着变中文
- 欢迎文档随语言切换（新增英文版）
- retranslateUi 负责菜单、动作、状态栏、侧栏文案的即时刷新

其它
- 删除 ExportDialog 与对应截图，README 同步

README.md

@@ -2,7 +2,7 @@
 
 一个轻量的跨平台 Markdown 编辑器，基于 **Qt 5 / C++17** 构建。
 
-当前版本 **0.5.1**。
+当前版本 **0.6.0**。
 
 ## 界面
 
@@ -14,10 +14,6 @@
 
 ![源代码模式](docs/screenshot-source.png)
 
-导出 PDF 前先给一个预览窗口，确认无误再选路径保存：
-
-![导出 PDF](docs/screenshot-export.png)
-
 ## 功能
 
 ### 编辑
@@ -62,14 +58,22 @@
 
 ### 导出 PDF
 
-**文件 → 导出 PDF…**（`Ctrl+E`）会先弹出预览窗口，里面就是最终排版；
-点「保存 PDF…」选个位置即可。A4 纸、16mm 页边距，预览和导出用的是同一份
-排版文档，所见即所得。
+**文件 → 导出 PDF…**（`Ctrl+E`）直接弹保存对话框，选个位置就导出，没有中间预览。
+A4 纸、16mm 页边距。
 
 导出用的是 Qt 自带的 `QPrinter` + `QTextDocument`，不需要额外的 PDF 库。
 支持标题、列表（含任务列表）、引用、代码块、行内代码、粗体 / 斜体 / 删除线、
 链接；图片只输出 alt 文字，表格暂时按原文输出。
 
+### 语言
+
+界面支持中文和英文，在 **视图 → 语言** 里切换，立即生效、不需要重启。
+选择会被记住。
+
+- 界面文案的中文就是源码本身；英文由 `translations/voiletmark_en.ts` 提供
+- Qt 自带的对话框（文件选择、消息框按钮）也会跟着切换，
+  中文用的是 Qt 官方的翻译文件
+
 ### 文件
 
 - 新建、打开、保存、另存为、最近打开（最多 8 条）
@@ -169,7 +173,7 @@ VoiletMark --screenshot a.png  # 渲染窗口截图后退出（调试 / 视觉
 | `Ctrl+N` / `Ctrl+O` / `Ctrl+S` | 新建 / 打开 / 保存 |
 | `Ctrl+Shift+S` | 另存为 |
 | `Ctrl+Shift+O` | 打开文件夹 |
-| `Ctrl+E` | 导出 PDF（先预览） |
+| `Ctrl+E` | 导出 PDF |
 | `Ctrl+B` | 显示 / 隐藏侧栏 |
 | `Ctrl+Shift+M` | 源代码模式 |
 | `Ctrl+1` ~ `Ctrl+6` | 设为 1–6 级标题（再按取消） |

VoiletMark.pro

@@ -1,6 +1,6 @@
 TEMPLATE = app
 TARGET   = VoiletMark
-VERSION  = 0.5.1
+VERSION  = 0.6.0
 
 QT += core gui widgets printsupport
 
@@ -23,7 +23,7 @@ SOURCES += \
     src/MarkdownEditor.cpp \
     src/MarkdownHighlighter.cpp \
     src/MarkdownRenderer.cpp \
-    src/ExportDialog.cpp \
+    src/LanguageManager.cpp \
     src/ThemeManager.cpp
 
 HEADERS += \
@@ -31,7 +31,7 @@ HEADERS += \
     src/MarkdownEditor.h \
     src/MarkdownHighlighter.h \
     src/MarkdownRenderer.h \
-    src/ExportDialog.h \
+    src/LanguageManager.h \
     src/ThemeManager.h
 
 # Linux 桌面集成：make install 之后能在应用菜单里找到

resources.qrc

@@ -1,5 +1,7 @@
 <RCC>
     <qresource prefix="/">
         <file>packaging/voiletmark.png</file>
+        <file>translations/voiletmark_en.qm</file>
+        <file>translations/qtbase_zh_CN.qm</file>
     </qresource>
 </RCC>

src/ExportDialog.cpp

@@ -1,111 +0,0 @@
-#include "ExportDialog.h"
-
-#include "MarkdownRenderer.h"
-
-#include <QDir>
-#include <QFileDialog>
-#include <QFileInfo>
-#include <QHBoxLayout>
-#include <QLabel>
-#include <QMessageBox>
-#include <QPageSize>
-#include <QPrinter>
-#include <QPushButton>
-#include <QScreen>
-#include <QTextBrowser>
-#include <QTextDocument>
-#include <QVBoxLayout>
-
-ExportDialog::ExportDialog(const QString &markdown, const QString &documentName,
-                           const QString &startDirectory, QWidget *parent)
-    : QDialog(parent)
-    , m_documentName(documentName)
-    , m_startDirectory(startDirectory)
-{
-    setWindowTitle(tr("导出 PDF — %1")
-                       .arg(documentName.isEmpty() ? tr("未命名") : documentName));
-
-    // 别让窗口比屏幕还高，否则底部的按钮会顶到屏幕外面去。
-    const QRect available = screen() ? screen()->availableGeometry() : QRect(0, 0, 1280, 900);
-    resize(qMin(900, available.width() - 80), qMin(860, available.height() - 100));
-
-    QVBoxLayout *layout = new QVBoxLayout(this);
-    layout->setContentsMargins(16, 16, 16, 12);
-    layout->setSpacing(10);
-
-    m_document = new QTextDocument(this);
-    MarkdownRenderer::render(markdown, m_document);
-    // A4 去掉 16mm 页边距后的正文宽度（96dpi 下的像素）：
-    // 预览和打印用同一个页宽，看到的就是导出的样子。
-    m_document->setPageSize(QSizeF(672.76, 1001.57));
-
-    m_preview = new QTextBrowser(this);
-    m_preview->setFrameShape(QFrame::NoFrame);
-    m_preview->setOpenExternalLinks(true);
-    m_preview->setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
-    m_preview->setFixedWidth(700);
-    m_preview->setDocument(m_document);
-    m_preview->setStyleSheet(QStringLiteral(
-        "QTextBrowser { background: #ffffff; color: #1f2328;"
-        " border: 1px solid #d8dde3; border-radius: 4px; }"));
-
-    QHBoxLayout *center = new QHBoxLayout;
-    center->addStretch(1);
-    center->addWidget(m_preview);
-    center->addStretch(1);
-    layout->addLayout(center, 1);
-
-    QLabel *hint = new QLabel(tr("A4 纸、16mm 页边距，内容和预览一致。"), this);
-    hint->setForegroundRole(QPalette::PlaceholderText);
-
-    QPushButton *saveButton = new QPushButton(tr("保存 PDF…"), this);
-    saveButton->setDefault(true);
-    QPushButton *closeButton = new QPushButton(tr("关闭"), this);
-
-    QHBoxLayout *buttons = new QHBoxLayout;
-    buttons->addWidget(hint);
-    buttons->addStretch(1);
-    buttons->addWidget(closeButton);
-    buttons->addWidget(saveButton);
-    layout->addLayout(buttons);
-
-    connect(closeButton, &QPushButton::clicked, this, &QDialog::reject);
-    connect(saveButton, &QPushButton::clicked, this, &ExportDialog::savePdf);
-}
-
-void ExportDialog::savePdf()
-{
-    QString suggested = m_documentName.isEmpty()
-                            ? tr("未命名")
-                            : QFileInfo(m_documentName).completeBaseName();
-    suggested += QStringLiteral(".pdf");
-
-    QString target = QFileDialog::getSaveFileName(
-        this, tr("保存 PDF"), QDir(m_startDirectory).filePath(suggested),
-        tr("PDF 文件 (*.pdf)"));
-    if (target.isEmpty())
-        return;
-
-    if (!target.endsWith(QStringLiteral(".pdf"), Qt::CaseInsensitive))
-        target += QStringLiteral(".pdf");
-
-    QPrinter printer(QPrinter::HighResolution);
-    printer.setOutputFormat(QPrinter::PdfFormat);
-    printer.setOutputFileName(target);
-    printer.setPageSize(QPageSize(QPageSize::A4));
-    printer.setPageMargins(QMarginsF(16, 16, 16, 16), QPageLayout::Millimeter);
-    printer.setDocName(QFileInfo(target).completeBaseName());
-
-    m_document->print(&printer);
-
-    if (!QFileInfo::exists(target) || QFileInfo(target).size() <= 0) {
-        QMessageBox::warning(this, tr("导出失败"),
-                             tr("没能写出「%1」，换个位置再试一次。")
-                                 .arg(QDir::toNativeSeparators(target)));
-        return;
-    }
-
-    QMessageBox::information(this, tr("导出完成"),
-                             tr("已保存到\n%1").arg(QDir::toNativeSeparators(target)));
-    accept();
-}

src/ExportDialog.h

@@ -1,24 +0,0 @@
-#pragma once
-
-#include <QDialog>
-
-class QTextBrowser;
-class QTextDocument;
-
-/// “导出 PDF”窗口：上方是排版后的预览，下方保存为 PDF。
-class ExportDialog : public QDialog
-{
-    Q_OBJECT
-
-public:
-    ExportDialog(const QString &markdown, const QString &documentName,
-                 const QString &startDirectory, QWidget *parent = nullptr);
-
-private:
-    void savePdf();
-
-    QTextBrowser *m_preview = nullptr;
-    QTextDocument *m_document = nullptr;
-    QString m_documentName;
-    QString m_startDirectory;
-};

src/LanguageManager.cpp

@@ -0,0 +1,82 @@
+#include "LanguageManager.h"
+
+#include <QCoreApplication>
+#include <QLocale>
+#include <QSettings>
+#include <QTranslator>
+
+LanguageManager *LanguageManager::instance()
+{
+    static LanguageManager *manager = new LanguageManager();
+    return manager;
+}
+
+LanguageManager::LanguageManager(QObject *parent)
+    : QObject(parent)
+{
+}
+
+QStringList LanguageManager::availableLanguages()
+{
+    return {QStringLiteral("zh_CN"), QStringLiteral("en")};
+}
+
+QString LanguageManager::displayName(const QString &code)
+{
+    if (code == QLatin1String("en"))
+        return QStringLiteral("English");
+    return QStringLiteral("中文");
+}
+
+void LanguageManager::initialize()
+{
+    QSettings settings;
+    QString code = settings.value(QStringLiteral("ui/language")).toString();
+    if (!availableLanguages().contains(code)) {
+        code = QLocale::system().language() == QLocale::English
+                   ? QStringLiteral("en")
+                   : QStringLiteral("zh_CN");
+    }
+    setLanguage(code);
+}
+
+void LanguageManager::setLanguage(const QString &code)
+{
+    const QString normalized =
+        (code == QLatin1String("en")) ? QStringLiteral("en") : QStringLiteral("zh_CN");
+
+    if (m_appTranslator) {
+        QCoreApplication::removeTranslator(m_appTranslator);
+        delete m_appTranslator;
+        m_appTranslator = nullptr;
+    }
+    if (m_qtTranslator) {
+        QCoreApplication::removeTranslator(m_qtTranslator);
+        delete m_qtTranslator;
+        m_qtTranslator = nullptr;
+    }
+
+    if (normalized == QLatin1String("en")) {
+        // 源码文案是中文，英文需要一份中文 → 英文的翻译。
+        auto *translator = new QTranslator(this);
+        if (translator->load(QStringLiteral(":/translations/voiletmark_en.qm"))) {
+            QCoreApplication::installTranslator(translator);
+            m_appTranslator = translator;
+        } else {
+            delete translator;
+        }
+    } else {
+        // 中文界面只需要把 Qt 自带的文件对话框 / 消息框也切过来。
+        auto *translator = new QTranslator(this);
+        if (translator->load(QStringLiteral(":/translations/qtbase_zh_CN.qm"))) {
+            QCoreApplication::installTranslator(translator);
+            m_qtTranslator = translator;
+        } else {
+            delete translator;
+        }
+    }
+
+    m_language = normalized;
+    QSettings().setValue(QStringLiteral("ui/language"), m_language);
+    emit languageChanged();
+}

src/LanguageManager.h

@@ -0,0 +1,37 @@
+#pragma once
+
+#include <QObject>
+
+class QTranslator;
+
+/// 界面语言管理：目前只支持中文（zh_CN）和英文（en）。
+///
+/// 源码里的界面文案是中文，所以中文不需要额外的翻译文件，
+/// 只要把 Qt 自带对话框（文件选择、消息框按钮等）切到中文；
+/// 英文则加载一份中文 → 英文的翻译文件。
+class LanguageManager : public QObject
+{
+    Q_OBJECT
+
+public:
+    static LanguageManager *instance();
+
+    /// 读取设置（首次按系统语言猜一个）并应用。
+    void initialize();
+
+    void setLanguage(const QString &code);
+    QString language() const { return m_language; }
+
+    static QStringList availableLanguages();
+    static QString displayName(const QString &code);
+
+signals:
+    void languageChanged();
+
+private:
+    explicit LanguageManager(QObject *parent = nullptr);
+
+    QString m_language = QStringLiteral("zh_CN");
+    QTranslator *m_appTranslator = nullptr;
+    QTranslator *m_qtTranslator = nullptr;
+};

src/MainWindow.cpp

@@ -1,7 +1,8 @@
 #include "MainWindow.h"
 
-#include "ExportDialog.h"
+#include "LanguageManager.h"
 #include "MarkdownEditor.h"
+#include "MarkdownRenderer.h"
 #include "ThemeManager.h"
 
 #include <QAction>
@@ -21,7 +22,10 @@
 #include <QMenu>
 #include <QMenuBar>
 #include <QMessageBox>
+#include <QPageLayout>
+#include <QPageSize>
 #include <QPixmap>
+#include <QPrinter>
 #include <QSaveFile>
 #include <QSettings>
 #include <QSignalBlocker>
@@ -83,6 +87,49 @@ int main()
 ---
 )VOILETMARK";
 
+const char kWelcomeTextEn[] = R"VOILETMARK(
+# Welcome to VoiletMark
+
+A lightweight cross-platform Markdown editor built with **Qt 5** and C++.
+
+## Quick start
+
+- `Ctrl+O` opens a file, `Ctrl+S` saves, `Ctrl+Shift+S` saves as
+- Drag a Markdown file into the window to open it
+- `Ctrl+1` – `Ctrl+6` set heading levels, `Ctrl+/` wraps a code block
+- `Ctrl+E` exports the document to PDF (A4)
+
+## Modes
+
+The default view is the editor: Markdown markers are hidden, headings are sized,
+and the line under the cursor reveals its raw markers.
+Click `<src>` in the status bar to see the source with line numbers.
+
+## Theme
+
+Follows the system light / dark setting by default;
+switch it under **View → Theme**.
+
+> Quotes, lists, `inline code`, **bold**, *italic*, ~~strikethrough~~
+> and [links](https://example.com) all render in place.
+
+- [x] Syntax highlighting
+- [x] Folder sidebar
+- [x] PDF export
+
+```cpp
+#include <cstdio>
+
+int main()
+{
+    std::printf("Hello, VoiletMark!\n");
+    return 0;
+}
+```
+
+---
+)VOILETMARK";
+
 } // namespace
 
 MainWindow::MainWindow(QWidget *parent)
@@ -109,6 +156,8 @@ MainWindow::MainWindow(QWidget *parent)
             this, &MainWindow::changeZoom);
     connect(m_editor, &MarkdownEditor::fileDropped,
             this, &MainWindow::openPath);
+    connect(LanguageManager::instance(), &LanguageManager::languageChanged,
+            this, &MainWindow::retranslateUi);
 
     showWelcomeDocument();
     updateEditActionStates();
@@ -266,40 +315,40 @@ void MainWindow::createSidebar()
 
 void MainWindow::createMenus()
 {
-    QMenu *fileMenu = menuBar()->addMenu(tr("文件"));
-    fileMenu->addAction(m_newAction);
-    fileMenu->addAction(m_openAction);
-    fileMenu->addAction(m_openFolderAction);
-    m_recentMenu = fileMenu->addMenu(tr("最近打开"));
-    fileMenu->addSeparator();
-    fileMenu->addAction(m_saveAction);
-    fileMenu->addAction(m_saveAsAction);
-    fileMenu->addAction(m_exportPdfAction);
-    fileMenu->addSeparator();
-    fileMenu->addAction(m_quitAction);
+    m_fileMenu = menuBar()->addMenu(tr("文件"));
+    m_fileMenu->addAction(m_newAction);
+    m_fileMenu->addAction(m_openAction);
+    m_fileMenu->addAction(m_openFolderAction);
+    m_recentMenu = m_fileMenu->addMenu(tr("最近打开"));
+    m_fileMenu->addSeparator();
+    m_fileMenu->addAction(m_saveAction);
+    m_fileMenu->addAction(m_saveAsAction);
+    m_fileMenu->addAction(m_exportPdfAction);
+    m_fileMenu->addSeparator();
+    m_fileMenu->addAction(m_quitAction);
 
-    QMenu *editMenu = menuBar()->addMenu(tr("编辑"));
-    editMenu->addAction(m_undoAction);
-    editMenu->addAction(m_redoAction);
-    editMenu->addSeparator();
-    editMenu->addAction(m_cutAction);
-    editMenu->addAction(m_copyAction);
-    editMenu->addAction(m_pasteAction);
-    editMenu->addSeparator();
-    editMenu->addAction(m_selectAllAction);
+    m_editMenu = menuBar()->addMenu(tr("编辑"));
+    m_editMenu->addAction(m_undoAction);
+    m_editMenu->addAction(m_redoAction);
+    m_editMenu->addSeparator();
+    m_editMenu->addAction(m_cutAction);
+    m_editMenu->addAction(m_copyAction);
+    m_editMenu->addAction(m_pasteAction);
+    m_editMenu->addSeparator();
+    m_editMenu->addAction(m_selectAllAction);
 
-    QMenu *viewMenu = menuBar()->addMenu(tr("视图"));
-    viewMenu->addAction(m_sidebarAction);
-    viewMenu->addAction(m_sourceModeAction);
-    viewMenu->addSeparator();
-    viewMenu->addAction(m_wrapAction);
-    viewMenu->addSeparator();
-    viewMenu->addAction(m_zoomInAction);
-    viewMenu->addAction(m_zoomOutAction);
-    viewMenu->addAction(m_zoomResetAction);
-    viewMenu->addSeparator();
+    m_viewMenu = menuBar()->addMenu(tr("视图"));
+    m_viewMenu->addAction(m_sidebarAction);
+    m_viewMenu->addAction(m_sourceModeAction);
+    m_viewMenu->addSeparator();
+    m_viewMenu->addAction(m_wrapAction);
+    m_viewMenu->addSeparator();
+    m_viewMenu->addAction(m_zoomInAction);
+    m_viewMenu->addAction(m_zoomOutAction);
+    m_viewMenu->addAction(m_zoomResetAction);
+    m_viewMenu->addSeparator();
 
-    QMenu *themeMenu = viewMenu->addMenu(tr("主题"));
+    m_themeMenu = m_viewMenu->addMenu(tr("主题"));
     QActionGroup *themeGroup = new QActionGroup(this);
     themeGroup->setExclusive(true);
 
@@ -312,7 +361,7 @@ void MainWindow::createMenus()
                             m_themeScheduleAction}) {
         action->setCheckable(true);
         themeGroup->addAction(action);
-        themeMenu->addAction(action);
+        m_themeMenu->addAction(action);
     }
     m_themeSystemAction->setChecked(true);
 
@@ -325,16 +374,33 @@ void MainWindow::createMenus()
     connect(m_themeScheduleAction, &QAction::triggered, this,
             [this] { applyThemeMode(static_cast<int>(ThemeManager::Mode::Schedule)); });
 
-    QMenu *formatMenu = menuBar()->addMenu(tr("格式"));
-    QMenu *headingMenu = formatMenu->addMenu(tr("标题"));
+    m_languageMenu = m_viewMenu->addMenu(tr("语言"));
+    QActionGroup *languageGroup = new QActionGroup(this);
+    languageGroup->setExclusive(true);
+    m_languageChineseAction =
+        new QAction(LanguageManager::displayName(QStringLiteral("zh_CN")), this);
+    m_languageEnglishAction =
+        new QAction(LanguageManager::displayName(QStringLiteral("en")), this);
+    for (QAction *action : {m_languageChineseAction, m_languageEnglishAction}) {
+        action->setCheckable(true);
+        languageGroup->addAction(action);
+        m_languageMenu->addAction(action);
+    }
+    connect(m_languageChineseAction, &QAction::triggered, this,
+            [this] { applyLanguage(QStringLiteral("zh_CN")); });
+    connect(m_languageEnglishAction, &QAction::triggered, this,
+            [this] { applyLanguage(QStringLiteral("en")); });
+
+    m_formatMenu = menuBar()->addMenu(tr("格式"));
+    m_headingMenu = m_formatMenu->addMenu(tr("标题"));
     for (QAction *headingAction : m_headingActions) {
         if (headingAction)
-            headingMenu->addAction(headingAction);
+            m_headingMenu->addAction(headingAction);
     }
-    formatMenu->addAction(m_codeBlockAction);
+    m_formatMenu->addAction(m_codeBlockAction);
 
-    QMenu *helpMenu = menuBar()->addMenu(tr("帮助"));
-    helpMenu->addAction(tr("关于 VoiletMark"), this, &MainWindow::showAbout);
+    m_helpMenu = menuBar()->addMenu(tr("帮助"));
+    m_aboutAction = m_helpMenu->addAction(tr("关于 VoiletMark"), this, &MainWindow::showAbout);
 }
 
 void MainWindow::createStatusBar()
@@ -446,9 +512,11 @@ QString MainWindow::startDirectory() const
 
 void MainWindow::showWelcomeDocument()
 {
-    QString text = QString::fromUtf8(kWelcomeText);
+    const bool english = LanguageManager::instance()->language() == QLatin1String("en");
+    QString text = QString::fromUtf8(english ? kWelcomeTextEn : kWelcomeText);
     if (text.startsWith(QLatin1Char('\n')))
         text.remove(0, 1);
+    m_welcomeText = text;
     m_editor->setPlainText(text);
     m_editor->applyBlockRhythm();
     m_editor->document()->setModified(false);
@@ -544,8 +612,37 @@ bool MainWindow::saveFileAs()
 
 void MainWindow::exportPdf()
 {
-    ExportDialog dialog(m_editor->toPlainText(), displayName(), startDirectory(), this);
-    dialog.exec();
+    QString suggested = m_currentPath.isEmpty() ? tr("未命名")
+                                                : QFileInfo(m_currentPath).completeBaseName();
+    suggested += QStringLiteral(".pdf");
+
+    QString target = QFileDialog::getSaveFileName(
+        this, tr("导出 PDF"), QDir(startDirectory()).filePath(suggested),
+        tr("PDF 文件 (*.pdf)"));
+    if (target.isEmpty())
+        return;
+    if (!target.endsWith(QStringLiteral(".pdf"), Qt::CaseInsensitive))
+        target += QStringLiteral(".pdf");
+
+    QTextDocument document;
+    MarkdownRenderer::render(m_editor->toPlainText(), &document);
+    document.setPageSize(QSizeF(672.76, 1001.57));
+
+    QPrinter printer(QPrinter::HighResolution);
+    printer.setOutputFormat(QPrinter::PdfFormat);
+    printer.setOutputFileName(target);
+    printer.setPageSize(QPageSize(QPageSize::A4));
+    printer.setPageMargins(QMarginsF(16, 16, 16, 16), QPageLayout::Millimeter);
+    printer.setDocName(QFileInfo(target).completeBaseName());
+    document.print(&printer);
+
+    if (!QFileInfo::exists(target) || QFileInfo(target).size() <= 0) {
+        QMessageBox::warning(this, tr("导出失败"),
+                             tr("没能写出「%1」，换个位置再试一次。")
+                                 .arg(QDir::toNativeSeparators(target)));
+        return;
+    }
+    statusBar()->showMessage(tr("已导出 %1").arg(QDir::toNativeSeparators(target)), 4000);
 }
 
 bool MainWindow::writeToFile(const QString &path)
@@ -667,6 +764,83 @@ void MainWindow::applyThemeMode(int mode)
     ThemeManager::instance()->setMode(static_cast<ThemeManager::Mode>(mode), true);
 }
 
+void MainWindow::applyLanguage(const QString &code)
+{
+    LanguageManager::instance()->setLanguage(code);
+}
+
+void MainWindow::retranslateUi()
+{
+    m_fileMenu->setTitle(tr("文件"));
+    m_editMenu->setTitle(tr("编辑"));
+    m_viewMenu->setTitle(tr("视图"));
+    m_formatMenu->setTitle(tr("格式"));
+    m_helpMenu->setTitle(tr("帮助"));
+    m_recentMenu->setTitle(tr("最近打开"));
+    m_themeMenu->setTitle(tr("主题"));
+    m_headingMenu->setTitle(tr("标题"));
+    m_languageMenu->setTitle(tr("语言"));
+
+    m_newAction->setText(tr("新建"));
+    m_openAction->setText(tr("打开…"));
+    m_openFolderAction->setText(tr("打开文件夹…"));
+    m_saveAction->setText(tr("保存"));
+    m_saveAsAction->setText(tr("另存为…"));
+    m_exportPdfAction->setText(tr("导出 PDF…"));
+    m_quitAction->setText(tr("退出"));
+
+    m_undoAction->setText(tr("撤销"));
+    m_redoAction->setText(tr("重做"));
+    m_cutAction->setText(tr("剪切"));
+    m_copyAction->setText(tr("复制"));
+    m_pasteAction->setText(tr("粘贴"));
+    m_selectAllAction->setText(tr("全选"));
+
+    m_sidebarAction->setText(tr("侧栏"));
+    m_sourceModeAction->setText(tr("源代码模式"));
+    m_wrapAction->setText(tr("自动换行"));
+    m_zoomInAction->setText(tr("放大"));
+    m_zoomOutAction->setText(tr("缩小"));
+    m_zoomResetAction->setText(tr("实际大小"));
+
+    m_themeSystemAction->setText(ThemeManager::modeLabel(ThemeManager::Mode::System));
+    m_themeLightAction->setText(ThemeManager::modeLabel(ThemeManager::Mode::Light));
+    m_themeDarkAction->setText(ThemeManager::modeLabel(ThemeManager::Mode::Dark));
+    m_themeScheduleAction->setText(ThemeManager::modeLabel(ThemeManager::Mode::Schedule));
+    m_themeScheduleAction->setToolTip(tr("6:00–18:00 使用浅色，其余时间使用深色"));
+
+    for (int level = 1; level <= 6; ++level) {
+        if (m_headingActions[level - 1])
+            m_headingActions[level - 1]->setText(tr("标题 %1").arg(level));
+    }
+    m_codeBlockAction->setText(tr("代码块"));
+    m_aboutAction->setText(tr("关于 VoiletMark"));
+
+    if (m_sidebarButton) {
+        m_sidebarButton->setText(tr("侧栏"));
+        m_sidebarButton->setToolTip(tr("显示 / 隐藏文件夹侧栏（Ctrl+B）"));
+    }
+    if (m_sourceButton)
+        m_sourceButton->setToolTip(tr("源代码模式：关闭语法高亮与行号（Ctrl+Shift+M）"));
+
+    const QString language = LanguageManager::instance()->language();
+    m_languageChineseAction->setChecked(language == QLatin1String("zh_CN"));
+    m_languageEnglishAction->setChecked(language == QLatin1String("en"));
+
+    // 侧栏、最近打开、欢迎文档都跟着换
+    m_displayedFolder.clear();
+    refreshRecentMenu();
+    refreshFolder();
+
+    if (m_currentPath.isEmpty() && !m_editor->document()->isModified()
+        && m_editor->toPlainText() == m_welcomeText) {
+        showWelcomeDocument();
+    }
+
+    updateWindowTitle();
+    updateStatusBar();
+}
+
 void MainWindow::showAbout()
 {
     QMessageBox box(this);

src/MainWindow.h

@@ -62,6 +62,8 @@ private:
     void resetZoom();
     void setWordWrapEnabled(bool enabled);
     void applyThemeMode(int mode);
+    void applyLanguage(const QString &code);
+    void retranslateUi();
     void showAbout();
 
     void updateStatusBar();
@@ -120,4 +122,18 @@ private:
     QAction *m_headingActions[6] = {nullptr, nullptr, nullptr, nullptr, nullptr, nullptr};
 
     QMenu *m_recentMenu = nullptr;
+    QMenu *m_fileMenu = nullptr;
+    QMenu *m_editMenu = nullptr;
+    QMenu *m_viewMenu = nullptr;
+    QMenu *m_formatMenu = nullptr;
+    QMenu *m_helpMenu = nullptr;
+    QMenu *m_themeMenu = nullptr;
+    QMenu *m_headingMenu = nullptr;
+    QMenu *m_languageMenu = nullptr;
+
+    QAction *m_aboutAction = nullptr;
+    QAction *m_languageChineseAction = nullptr;
+    QAction *m_languageEnglishAction = nullptr;
+
+    QString m_welcomeText;
 };

src/main.cpp

@@ -1,3 +1,4 @@
+#include "LanguageManager.h"
 #include "MainWindow.h"
 #include "ThemeManager.h"
 
@@ -51,6 +52,7 @@ int main(int argc, char *argv[])
             mode = ThemeManager::Mode::System;
     }
     ThemeManager::instance()->initialize(mode, false);
+    LanguageManager::instance()->initialize();
 
     MainWindow window;
     window.show();

translations/voiletmark_en.ts

@@ -0,0 +1,395 @@
+<?xml version='1.0' encoding='utf-8'?>
+<TS version="2.1" language="en_US">
+<context>
+    <name>MainWindow</name>
+    <message>
+        <location filename="../src/MainWindow.cpp" line="167" />
+        <location filename="../src/MainWindow.cpp" line="781" />
+        <source>新建</source>
+        <translation>New</translation>
+    </message>
+    <message>
+        <location filename="../src/MainWindow.cpp" line="171" />
+        <location filename="../src/MainWindow.cpp" line="782" />
+        <source>打开…</source>
+        <translation>Open…</translation>
+    </message>
+    <message>
+        <location filename="../src/MainWindow.cpp" line="175" />
+        <location filename="../src/MainWindow.cpp" line="784" />
+        <source>保存</source>
+        <translation>Save</translation>
+    </message>
+    <message>
+        <location filename="../src/MainWindow.cpp" line="179" />
+        <location filename="../src/MainWindow.cpp" line="785" />
+        <source>另存为…</source>
+        <translation>Save As…</translation>
+    </message>
+    <message>
+        <location filename="../src/MainWindow.cpp" line="183" />
+        <location filename="../src/MainWindow.cpp" line="786" />
+        <source>导出 PDF…</source>
+        <translation>Export PDF…</translation>
+    </message>
+    <message>
+        <location filename="../src/MainWindow.cpp" line="187" />
+        <location filename="../src/MainWindow.cpp" line="787" />
+        <source>退出</source>
+        <translation>Quit</translation>
+    </message>
+    <message>
+        <location filename="../src/MainWindow.cpp" line="191" />
+        <location filename="../src/MainWindow.cpp" line="789" />
+        <source>撤销</source>
+        <translation>Undo</translation>
+    </message>
+    <message>
+        <location filename="../src/MainWindow.cpp" line="195" />
+        <location filename="../src/MainWindow.cpp" line="790" />
+        <source>重做</source>
+        <translation>Redo</translation>
+    </message>
+    <message>
+        <location filename="../src/MainWindow.cpp" line="199" />
+        <location filename="../src/MainWindow.cpp" line="791" />
+        <source>剪切</source>
+        <translation>Cut</translation>
+    </message>
+    <message>
+        <location filename="../src/MainWindow.cpp" line="203" />
+        <location filename="../src/MainWindow.cpp" line="792" />
+        <source>复制</source>
+        <translation>Copy</translation>
+    </message>
+    <message>
+        <location filename="../src/MainWindow.cpp" line="207" />
+        <location filename="../src/MainWindow.cpp" line="793" />
+        <source>粘贴</source>
+        <translation>Paste</translation>
+    </message>
+    <message>
+        <location filename="../src/MainWindow.cpp" line="211" />
+        <location filename="../src/MainWindow.cpp" line="794" />
+        <source>全选</source>
+        <translation>Select All</translation>
+    </message>
+    <message>
+        <location filename="../src/MainWindow.cpp" line="215" />
+        <location filename="../src/MainWindow.cpp" line="798" />
+        <source>自动换行</source>
+        <translation>Word Wrap</translation>
+    </message>
+    <message>
+        <location filename="../src/MainWindow.cpp" line="220" />
+        <location filename="../src/MainWindow.cpp" line="799" />
+        <source>放大</source>
+        <translation>Zoom In</translation>
+    </message>
+    <message>
+        <location filename="../src/MainWindow.cpp" line="224" />
+        <location filename="../src/MainWindow.cpp" line="800" />
+        <source>缩小</source>
+        <translation>Zoom Out</translation>
+    </message>
+    <message>
+        <location filename="../src/MainWindow.cpp" line="228" />
+        <location filename="../src/MainWindow.cpp" line="801" />
+        <source>实际大小</source>
+        <translation>Actual Size</translation>
+    </message>
+    <message>
+        <location filename="../src/MainWindow.cpp" line="237" />
+        <location filename="../src/MainWindow.cpp" line="783" />
+        <source>打开文件夹…</source>
+        <translation>Open Folder…</translation>
+    </message>
+    <message>
+        <location filename="../src/MainWindow.cpp" line="241" />
+        <location filename="../src/MainWindow.cpp" line="407" />
+        <location filename="../src/MainWindow.cpp" line="796" />
+        <location filename="../src/MainWindow.cpp" line="817" />
+        <source>侧栏</source>
+        <translation>Sidebar</translation>
+    </message>
+    <message>
+        <location filename="../src/MainWindow.cpp" line="255" />
+        <location filename="../src/MainWindow.cpp" line="797" />
+        <source>源代码模式</source>
+        <translation>Source Mode</translation>
+    </message>
+    <message>
+        <location filename="../src/MainWindow.cpp" line="260" />
+        <location filename="../src/MainWindow.cpp" line="813" />
+        <source>代码块</source>
+        <translation>Code Block</translation>
+    </message>
+    <message>
+        <location filename="../src/MainWindow.cpp" line="267" />
+        <location filename="../src/MainWindow.cpp" line="811" />
+        <source>标题 %1</source>
+        <translation>Heading %1</translation>
+    </message>
+    <message>
+        <location filename="../src/MainWindow.cpp" line="278" />
+        <source>文件夹</source>
+        <translation>Folder</translation>
+    </message>
+    <message>
+        <location filename="../src/MainWindow.cpp" line="289" />
+        <location filename="../src/MainWindow.cpp" line="961" />
+        <source>未打开文件夹</source>
+        <translation>No folder open</translation>
+    </message>
+    <message>
+        <location filename="../src/MainWindow.cpp" line="315" />
+        <location filename="../src/MainWindow.cpp" line="771" />
+        <source>文件</source>
+        <translation>File</translation>
+    </message>
+    <message>
+        <location filename="../src/MainWindow.cpp" line="319" />
+        <location filename="../src/MainWindow.cpp" line="776" />
+        <source>最近打开</source>
+        <translation>Recent Files</translation>
+    </message>
+    <message>
+        <location filename="../src/MainWindow.cpp" line="327" />
+        <location filename="../src/MainWindow.cpp" line="772" />
+        <source>编辑</source>
+        <translation>Edit</translation>
+    </message>
+    <message>
+        <location filename="../src/MainWindow.cpp" line="337" />
+        <location filename="../src/MainWindow.cpp" line="773" />
+        <source>视图</source>
+        <translation>View</translation>
+    </message>
+    <message>
+        <location filename="../src/MainWindow.cpp" line="348" />
+        <location filename="../src/MainWindow.cpp" line="777" />
+        <source>主题</source>
+        <translation>Theme</translation>
+    </message>
+    <message>
+        <location filename="../src/MainWindow.cpp" line="356" />
+        <location filename="../src/MainWindow.cpp" line="807" />
+        <source>6:00–18:00 使用浅色，其余时间使用深色</source>
+        <translation>Light from 6:00 to 18:00, dark the rest of the day</translation>
+    </message>
+    <message>
+        <location filename="../src/MainWindow.cpp" line="374" />
+        <location filename="../src/MainWindow.cpp" line="779" />
+        <source>语言</source>
+        <translation>Language</translation>
+    </message>
+    <message>
+        <location filename="../src/MainWindow.cpp" line="391" />
+        <location filename="../src/MainWindow.cpp" line="774" />
+        <source>格式</source>
+        <translation>Format</translation>
+    </message>
+    <message>
+        <location filename="../src/MainWindow.cpp" line="392" />
+        <location filename="../src/MainWindow.cpp" line="778" />
+        <source>标题</source>
+        <translation>Heading</translation>
+    </message>
+    <message>
+        <location filename="../src/MainWindow.cpp" line="399" />
+        <location filename="../src/MainWindow.cpp" line="775" />
+        <source>帮助</source>
+        <translation>Help</translation>
+    </message>
+    <message>
+        <location filename="../src/MainWindow.cpp" line="400" />
+        <location filename="../src/MainWindow.cpp" line="814" />
+        <location filename="../src/MainWindow.cpp" line="844" />
+        <source>关于 VoiletMark</source>
+        <translation>About VoiletMark</translation>
+    </message>
+    <message>
+        <location filename="../src/MainWindow.cpp" line="411" />
+        <location filename="../src/MainWindow.cpp" line="818" />
+        <source>显示 / 隐藏文件夹侧栏（Ctrl+B）</source>
+        <translation>Show / hide the folder sidebar (Ctrl+B)</translation>
+    </message>
+    <message>
+        <location filename="../src/MainWindow.cpp" line="419" />
+        <location filename="../src/MainWindow.cpp" line="821" />
+        <source>源代码模式：关闭语法高亮与行号（Ctrl+Shift+M）</source>
+        <translation>Source mode: turn off highlighting and line numbers (Ctrl+Shift+M)</translation>
+    </message>
+    <message>
+        <location filename="../src/MainWindow.cpp" line="497" />
+        <location filename="../src/MainWindow.cpp" line="612" />
+        <source>未命名</source>
+        <translation>Untitled</translation>
+    </message>
+    <message>
+        <location filename="../src/MainWindow.cpp" line="546" />
+        <source>打开 Markdown 文件</source>
+        <translation>Open Markdown File</translation>
+    </message>
+    <message>
+        <location filename="../src/MainWindow.cpp" line="547" />
+        <source>Markdown 文件 (*.md *.markdown *.mdown *.mkd);;文本文件 (*.txt);;所有文件 (*)</source>
+        <translation>Markdown files (*.md *.markdown *.mdown *.mkd);;Text files (*.txt);;All files (*)</translation>
+    </message>
+    <message>
+        <location filename="../src/MainWindow.cpp" line="564" />
+        <source>无法打开文件</source>
+        <translation>Cannot Open File</translation>
+    </message>
+    <message>
+        <location filename="../src/MainWindow.cpp" line="565" />
+        <source>读取「%1」失败：%2</source>
+        <translation>Could not read "%1": %2</translation>
+    </message>
+    <message>
+        <location filename="../src/MainWindow.cpp" line="599" />
+        <source>另存为</source>
+        <translation>Save As</translation>
+    </message>
+    <message>
+        <location filename="../src/MainWindow.cpp" line="600" />
+        <source>Markdown 文件 (*.md);;文本文件 (*.txt);;所有文件 (*)</source>
+        <translation>Markdown files (*.md);;Text files (*.txt);;All files (*)</translation>
+    </message>
+    <message>
+        <location filename="../src/MainWindow.cpp" line="617" />
+        <source>导出 PDF</source>
+        <translation>Export PDF</translation>
+    </message>
+    <message>
+        <location filename="../src/MainWindow.cpp" line="618" />
+        <source>PDF 文件 (*.pdf)</source>
+        <translation>PDF files (*.pdf)</translation>
+    </message>
+    <message>
+        <location filename="../src/MainWindow.cpp" line="637" />
+        <source>导出失败</source>
+        <translation>Export Failed</translation>
+    </message>
+    <message>
+        <location filename="../src/MainWindow.cpp" line="638" />
+        <source>没能写出「%1」，换个位置再试一次。</source>
+        <translation>Could not write "%1". Try another location.</translation>
+    </message>
+    <message>
+        <location filename="../src/MainWindow.cpp" line="642" />
+        <source>已导出 %1</source>
+        <translation>Exported to %1</translation>
+    </message>
+    <message>
+        <location filename="../src/MainWindow.cpp" line="657" />
+        <location filename="../src/MainWindow.cpp" line="664" />
+        <location filename="../src/MainWindow.cpp" line="669" />
+        <source>无法保存文件</source>
+        <translation>Cannot Save File</translation>
+    </message>
+    <message>
+        <location filename="../src/MainWindow.cpp" line="658" />
+        <source>写入「%1」失败：%2</source>
+        <translation>Could not write "%1": %2</translation>
+    </message>
+    <message>
+        <location filename="../src/MainWindow.cpp" line="665" />
+        <source>写入「%1」时发生错误。</source>
+        <translation>An error occurred while writing "%1".</translation>
+    </message>
+    <message>
+        <location filename="../src/MainWindow.cpp" line="670" />
+        <source>提交「%1」失败：%2</source>
+        <translation>Could not commit "%1": %2</translation>
+    </message>
+    <message>
+        <location filename="../src/MainWindow.cpp" line="678" />
+        <source>已保存 %1</source>
+        <translation>Saved to %1</translation>
+    </message>
+    <message>
+        <location filename="../src/MainWindow.cpp" line="688" />
+        <source>VoiletMark</source>
+        <translation>VoiletMark</translation>
+    </message>
+    <message>
+        <location filename="../src/MainWindow.cpp" line="689" />
+        <source>「%1」有未保存的修改，是否保存？</source>
+        <translation>"%1" has unsaved changes. Save them?</translation>
+    </message>
+    <message>
+        <location filename="../src/MainWindow.cpp" line="713" />
+        <source>%1[*] — VoiletMark</source>
+        <translation>%1[*] — VoiletMark</translation>
+    </message>
+    <message>
+        <location filename="../src/MainWindow.cpp" line="732" />
+        <source>行 %1，列 %2</source>
+        <translation>Line %1, Col %2</translation>
+    </message>
+    <message>
+        <location filename="../src/MainWindow.cpp" line="734" />
+        <source>    已选 %1 字</source>
+        <translation>    %1 selected</translation>
+    </message>
+    <message>
+        <location filename="../src/MainWindow.cpp" line="735" />
+        <source>    %1 字</source>
+        <translation>    %1 chars</translation>
+    </message>
+    <message>
+        <location filename="../src/MainWindow.cpp" line="848" />
+        <source>&lt;h3&gt;VoiletMark %1&lt;/h3&gt;&lt;p&gt;一个轻量的跨平台 Markdown 编辑器。&lt;/p&gt;&lt;p&gt;基于 Qt %2 与 C++17 构建。&lt;/p&gt;</source>
+        <translation>&lt;h3&gt;VoiletMark %1&lt;/h3&gt;&lt;p&gt;A lightweight cross-platform Markdown editor.&lt;/p&gt;&lt;p&gt;Built with Qt %2 and C++17.&lt;/p&gt;</translation>
+    </message>
+    <message>
+        <location filename="../src/MainWindow.cpp" line="883" />
+        <source>（暂无记录）</source>
+        <translation>(none)</translation>
+    </message>
+    <message>
+        <location filename="../src/MainWindow.cpp" line="896" />
+        <source>清空列表</source>
+        <translation>Clear List</translation>
+    </message>
+    <message>
+        <location filename="../src/MainWindow.cpp" line="906" />
+        <source>打开文件夹</source>
+        <translation>Open Folder</translation>
+    </message>
+    <message>
+        <location filename="../src/MainWindow.cpp" line="962" />
+        <source>文件 → 打开文件夹…</source>
+        <translation>File → Open Folder…</translation>
+    </message>
+    <message>
+        <location filename="../src/MainWindow.cpp" line="998" />
+        <source>（没有 Markdown 文件）</source>
+        <translation>(no Markdown files)</translation>
+    </message>
+</context>
+<context>
+    <name>QObject</name>
+    <message>
+        <location filename="../src/ThemeManager.cpp" line="354" />
+        <source>浅色</source>
+        <translation>Light</translation>
+    </message>
+    <message>
+        <location filename="../src/ThemeManager.cpp" line="355" />
+        <source>深色</source>
+        <translation>Dark</translation>
+    </message>
+    <message>
+        <location filename="../src/ThemeManager.cpp" line="356" />
+        <source>按时段自动</source>
+        <translation>Scheduled</translation>
+    </message>
+    <message>
+        <location filename="../src/ThemeManager.cpp" line="359" />
+        <source>跟随系统</source>
+        <translation>Follow System</translation>
+    </message>
+</context>
+</TS>