Qt实现语言切换的完整方案

news2025/4/25 10:11:33

在Qt中实现语言动态切换需要以下几个关键步骤，我将提供一个完整的实现方案：

一、准备工作

在代码中使用tr()标记所有需要翻译的字符串

cpp
```
button->setText(tr("Submit"));
```

创建翻译文件

在.pro文件中添加：

qmake

TRANSLATIONS = translations/myapp_zh_CN.ts \
              translations/myapp_en_US.ts

二、核心实现类

1. 语言管理器头文件 (LanguageManager.h)

cpp

#ifndef LANGUAGEMANAGER_H
#define LANGUAGEMANAGER_H

#include <QObject>
#include <QTranslator>
#include <QMap>

class LanguageManager : public QObject
{
    Q_OBJECT
public:
    static LanguageManager* instance();
    
    // 可用语言列表
    QMap<QString, QString> availableLanguages() const;
    
    // 设置当前语言
    void setCurrentLanguage(const QString& languageCode);
    
    // 获取当前语言
    QString currentLanguage() const;

signals:
    // 语言改变信号
    void languageChanged();

protected:
    explicit LanguageManager(QObject *parent = nullptr);

private:
    void loadTranslations();
    
    static LanguageManager* m_instance;
    QTranslator* m_appTranslator;
    QTranslator* m_qtTranslator;
    QString m_currentLanguage;
    QMap<QString, QString> m_languages; // <code, displayName>
};

#endif // LANGUAGEMANAGER_H

2. 语言管理器实现 (LanguageManager.cpp)

cpp

#include "LanguageManager.h"
#include <QApplication>
#include <QDir>
#include <QDebug>
#include <QLibraryInfo>
#include <QSettings>

LanguageManager* LanguageManager::m_instance = nullptr;

LanguageManager::LanguageManager(QObject *parent) : QObject(parent)
{
    m_appTranslator = new QTranslator(this);
    m_qtTranslator = new QTranslator(this);
    
    // 初始化可用语言
    m_languages = {
        {"en_US", "English"},
        {"zh_CN", "简体中文"},
        {"ja_JP", "日本語"}
    };
    
    loadTranslations();
}

LanguageManager* LanguageManager::instance()
{
    if (!m_instance) {
        m_instance = new LanguageManager(qApp);
    }
    return m_instance;
}

QMap<QString, QString> LanguageManager::availableLanguages() const
{
    return m_languages;
}

void LanguageManager::setCurrentLanguage(const QString &languageCode)
{
    if (!m_languages.contains(languageCode) || m_currentLanguage == languageCode) {
        return;
    }
    
    // 加载应用程序翻译
    bool loadSuccess = m_appTranslator->load(QString(":/translations/myapp_%1.qm").arg(languageCode));
    
    if (loadSuccess) {
        QApplication::installTranslator(m_appTranslator);
        
        // 加载Qt基础库翻译
        if (m_qtTranslator->load(QString("qt_%1").arg(languageCode), 
                               QLibraryInfo::location(QLibraryInfo::TranslationsPath))) {
            QApplication::installTranslator(m_qtTranslator);
        }
        
        m_currentLanguage = languageCode;
        
        // 保存到设置
        QSettings settings;
        settings.setValue("Language", languageCode);
        
        emit languageChanged();
    } else {
        qWarning() << "Failed to load translation for" << languageCode;
    }
}

QString LanguageManager::currentLanguage() const
{
    return m_currentLanguage;
}

void LanguageManager::loadTranslations()
{
    QSettings settings;
    QString lang = settings.value("Language", QLocale::system().name()).toString();
    
    // 如果设置的语言不可用，则使用系统语言或默认英语
    if (!m_languages.contains(lang)) {
        lang = m_languages.contains(QLocale::system().name()) ? 
               QLocale::system().name() : "en_US";
    }
    
    setCurrentLanguage(lang);
}

三、使用示例

1. 主窗口实现

cpp

// MainWindow.h
#include <QMainWindow>
#include "LanguageManager.h"

namespace Ui {
class MainWindow;
}

class MainWindow : public QMainWindow
{
    Q_OBJECT

public:
    explicit MainWindow(QWidget *parent = nullptr);
    ~MainWindow();

protected:
    void changeEvent(QEvent *e) override;

private slots:
    void onLanguageChanged();
    void on_actionChinese_triggered();
    void on_actionEnglish_triggered();

private:
    Ui::MainWindow *ui;
    void updateUI();
};

// MainWindow.cpp
#include "MainWindow.h"
#include "ui_MainWindow.h"

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);
    
    // 连接语言改变信号
    connect(LanguageManager::instance(), &LanguageManager::languageChanged,
            this, &MainWindow::onLanguageChanged);
    
    updateUI();
}

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

void MainWindow::changeEvent(QEvent *e)
{
    QMainWindow::changeEvent(e);
    if (e->type() == QEvent::LanguageChange) {
        ui->retranslateUi(this);
        updateUI();
    }
}

void MainWindow::onLanguageChanged()
{
    // 语言改变后的处理
    updateUI();
}

void MainWindow::updateUI()
{
    // 更新非UI文件中的文本
    setWindowTitle(tr("Multilingual Application"));
    statusBar()->showMessage(tr("Current language: %1")
                            .arg(LanguageManager::instance()->currentLanguage()));
}

void MainWindow::on_actionChinese_triggered()
{
    LanguageManager::instance()->setCurrentLanguage("zh_CN");
}

void MainWindow::on_actionEnglish_triggered()
{
    LanguageManager::instance()->setCurrentLanguage("en_US");
}

2. 主函数初始化

cpp

#include <QApplication>
#include "MainWindow.h"
#include "LanguageManager.h"

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    
    // 初始化语言管理器
    LanguageManager::instance()->>setCurrentLanguage("zh_CN");
    
    MainWindow w;
    w.show();
    
    return a.exec();
}

四、说明

翻译文件生成流程：

bash

lupdate myproject.pro  # 生成.ts文件
linguist translations/myapp_zh_CN.ts  # 使用Qt Linguist翻译
lrelease myproject.pro  # 生成.qm文件

资源文件(.qrc)配置：

xml

<RCC>
    <qresource prefix="/">
        <file>translations/myapp_zh_CN.qm</file>
        <file>translations/myapp_en_US.qm</file>
    </qresource>
</RCC>