qt语言国际化（翻译），并实现多窗口同时翻译

一、.pro文件中添加支持的语言

在.pro文件中添加下面几句，支持中文和英文

TRANSLATIONS = lanague_cn.ts\
                lanague_en.ts

二、通过qt语言家更新翻译生成.ts文件

完成以后在工程目录可以看到.ts文件

三、通过linguist翻译文件

打开文件

将两个文件同时选中，打开。

四、Qt语言家发布文字生成.qm文件

五、使用翻译文件进行多语言切换

为了方便多窗口同时切换，使用单例类进行，源码如下：

languageHelper.h

#ifndef LANGUAGEHELPER_H
#define LANGUAGEHELPER_H

#include 
#include 
#include 
#include 

class LanguageHelper : public QObject
{
    Q_OBJECT
public:
    enum language {
        chinese,
        english,
        undefined
    };
signals:
    void languageChaned();
private:
    explicit LanguageHelper();
    ~LanguageHelper();
    LanguageHelper(LanguageHelper&) = delete;
    LanguageHelper operator=(const LanguageHelper &) = delete;

public:
    static LanguageHelper *getInstance()
    {
        static QMutex mutex;

        mutex.lock();
        if(languageHelper == nullptr)
        {
            languageHelper = new LanguageHelper();
        }
        mutex.unlock();
        return languageHelper;
    }
    static void quit();
    bool changeLanguage(language l);

private:
    static LanguageHelper *languageHelper;
    QTranslator* translator = nullptr;
    language currentLanguage = language::undefined;
};

#endif // LANGUAGEHELPER_H

languageHelper.cpp

#include "languageHelper.h"

LanguageHelper *LanguageHelper::languageHelper = nullptr;

LanguageHelper::LanguageHelper()
{
    this->translator = new QTranslator();

}

LanguageHelper::~LanguageHelper()
{
    if(this->translator)
    {
        delete this->translator;
        this->translator = nullptr;
    }
    qDebug()<<"~LanguageHelper";
}

void LanguageHelper::quit()
{
    if(languageHelper)
        delete languageHelper;
}

bool LanguageHelper::changeLanguage(language l)
{
    if(l == this->currentLanguage || l == language::undefined)
        return true;
    bool ret = false;
    switch(l)
    {
        case chinese:
        {
            if (this->translator != nullptr)
                qApp->removeTranslator(this->translator);
            ret = this->translator->load("E:/CompanyProjects/KPMG/winccTemp/language/Language/lanague_cn.qm");
            if (ret)
            {
                bool install = qApp->installTranslator(this->translator);
                if (install == false)
                    return false;
            }
            else
                return false;


        }break;
        case english:
        {
            if (this->translator != nullptr)
                qApp->removeTranslator(this->translator);
            ret = this->translator->load("E:/CompanyProjects/KPMG/winccTemp/language/Language/lanague_en.qm");
            if (ret)
            {
                bool install = qApp->installTranslator(this->translator);
                if (install == false)
                    return false;
            }
            else
                return false;
        }break;
        case undefined:
        {

        }break;
    }
    if (ret) {
        this->currentLanguage = l;
        emit languageChaned();
    }
}

通过按钮切换语言：

void MainWindow::on_btnChinese_clicked()
{
    LanguageHelper::getInstance()->changeLanguage(LanguageHelper::chinese);
}


void MainWindow::on_btnEnglish_clicked()
{
    LanguageHelper::getInstance()->changeLanguage(LanguageHelper::english);
}

需要注意的是，在需要实时翻译的界面需要实现languageChaned信号的绑定，然后调用ui->retranslateUi(this);函数，如下：

    connect(LanguageHelper::getInstance(),&LanguageHelper::languageChaned,this,
            [=]()
            {
                ui->retranslateUi(this);
            });