一般情况下，需要翻译的内容处于UI相关的控件上，使用Qt提供的内置控件时，可以通过Qt Lingust直接再Widget相关的类中翻译；

如果有自定义控件，且控件中有需要翻译的内容的情形的处理：

1、显示添加翻译相关的代码；

2、将自定义控件写成插件，利用内置控件相同的机制来进行翻译；

代码

main.cpp

#include "QtVSMultiLanguage.h"
#include <QtWidgets/QApplication>
#include "Linguist.h"int main(int argc, char *argv[])
{QApplication a(argc, argv);CLinguist* lin = CLinguist::GetLinguistInstance();lin->ChangeLanguage(Language::zh_cn);QtVSMultiLanguage w;w.show();return a.exec();
}

 Linguist.h

// Linguist.h
#pragma once
/*
语言家，配置当前系统的语言
*/#include <QObject>
#include <qtranslator.h>enum Language
{zh_cn,en_us,undefined
};class CLinguist :public QObject
{Q_OBJECT
private:CLinguist();public:// 当前语言 简体中文、英文、未定义Language m_CurrentLanguage = Language::undefined;// 切换语言void ChangeLanguage(Language lan);static  CLinguist * GetLinguistInstance();
private:static CLinguist * linguist;QTranslator * m_trans;
signals:// 语言切换信号，通知当前系统语言已经被切换void LanguageChaned();
};

Linguist.cpp

#include "Linguist.h"
#include <QtCore/QCoreApplication>CLinguist * CLinguist::linguist = nullptr;
CLinguist::CLinguist() :m_trans(new QTranslator)
{
}CLinguist * CLinguist::GetLinguistInstance()
{if (nullptr == linguist){linguist = new CLinguist;}return linguist;
}void CLinguist::ChangeLanguage(Language lan)
{if (lan == this->m_CurrentLanguage || lan == Language::undefined) return;bool ret;switch (lan){case zh_cn:if (nullptr != m_trans){qApp->removeTranslator(m_trans);}ret = m_trans->load("qtvsmultilanguage_zh.qm");if (ret){qApp->installTranslator(m_trans);}break;case en_us:if (nullptr != m_trans){qApp->removeTranslator(m_trans);}ret = m_trans->load("qtvsmultilanguage_en.qm");if (ret){qApp->installTranslator(m_trans);}break;default:break;}if (ret){this->m_CurrentLanguage = lan;// 发出语言被切换的信号emit LanguageChaned();}
}

 QtVSMultiLanguage.ui

<?xml version="1.0" encoding="UTF-8"?>
<ui version="4.0"><class>QtVSMultiLanguageClass</class><widget class="QMainWindow" name="QtVSMultiLanguageClass"><property name="geometry"><rect><x>0</x><y>0</y><width>653</width><height>416</height></rect></property><property name="windowTitle"><string>QtVSMultiLanguage</string></property><widget class="QWidget" name="centralWidget"><widget class="QWidget" name="layoutWidget"><property name="geometry"><rect><x>50</x><y>20</y><width>354</width><height>185</height></rect></property><layout class="QVBoxLayout" name="verticalLayout"><item><layout class="QHBoxLayout" name="horizontalLayout"><item><widget class="QLabel" name="UserNameLabel"><property name="text"><string>UserName:</string></property></widget></item><item><spacer name="horizontalSpacer"><property name="orientation"><enum>Qt::Horizontal</enum></property><property name="sizeHint" stdset="0"><size><width>28</width><height>20</height></size></property></spacer></item><item><widget class="QTextEdit" name="UserNametextEdit"/></item></layout></item><item><layout class="QHBoxLayout" name="horizontalLayout_2"><item><widget class="QLabel" name="PassWordLabel"><property name="text"><string>PassWord:</string></property></widget></item><item><spacer name="horizontalSpacer_2"><property name="orientation"><enum>Qt::Horizontal</enum></property><property name="sizeHint" stdset="0"><size><width>28</width><height>20</height></size></property></spacer></item><item><widget class="QTextEdit" name="PassWordtextEdit"/></item></layout></item><item><layout class="QHBoxLayout" name="horizontalLayout_3"><item><widget class="QPushButton" name="SwitchpushButton"><property name="text"><string>SwitchLanguage</string></property></widget></item><item><spacer name="horizontalSpacer_3"><property name="orientation"><enum>Qt::Horizontal</enum></property><property name="sizeHint" stdset="0"><size><width>40</width><height>20</height></size></property></spacer></item><item><widget class="QPushButton" name="LoginpushButton"><property name="text"><string>Login</string></property></widget></item><item><spacer name="horizontalSpacer_4"><property name="orientation"><enum>Qt::Horizontal</enum></property><property name="sizeHint" stdset="0"><size><width>40</width><height>20</height></size></property></spacer></item><item><widget class="QPushButton" name="CancelpushButton"><property name="text"><string>Cancel</string></property></widget></item></layout></item></layout></widget><widget class="ForceLinePointWidget" name="PointInfoWidget"><property name="geometry"><rect><x>90</x><y>250</y><width>440</width><height>40</height></rect></property><property name="toolTip"><string>The current time</string></property><property name="whatsThis"><string>The analog clock widget displays the current time.</string></property><property name="pointName"><string>FemurHeadCenter</string></property></widget></widget><widget class="QMenuBar" name="menuBar"><property name="geometry"><rect><x>0</x><y>0</y><width>653</width><height>23</height></rect></property></widget><widget class="QToolBar" name="mainToolBar"><attribute name="toolBarArea"><enum>TopToolBarArea</enum></attribute><attribute name="toolBarBreak"><bool>false</bool></attribute></widget><widget class="QStatusBar" name="statusBar"/></widget><layoutdefault spacing="6" margin="11"/><customwidgets><customwidget><class>ForceLinePointWidget</class><extends>QWidget</extends><header>ForceLinePointWidget.h</header></customwidget></customwidgets><resources><include location="QtVSMultiLanguage.qrc"/></resources><connections/>
</ui>

https://gitee.com/beibeix/qt-samples/tree/master/QtVSMultiLanguage

结果