本来用qmake使用pro文件很简单的一件事，结果用cmake折腾了半天。
何必呢~

参考：QT6.3 CMake 多语言切换

这是我的

cmake_minimum_required(VERSION 3.16)

project(testQml3_6 VERSION 0.1 LANGUAGES CXX)

set(CMAKE_AUTOMOC ON)
set(CMAKE_CXX_STANDARD_REQUIRED ON)

find_package(Qt6 6.2 COMPONENTS Quick REQUIRED LinguistTools)

set(OUR_TS_FILES testQml3_6_zh_CN.ts testQml3_6_de.ts)

qt_add_executable(apptestQml3_6
    main.cpp
    ${OUR_TS_FILES}
)

qt_create_translation(QM_FILES ${CMAKE_SOURCE_DIR} ${OUR_TS_FILES})

qt_add_qml_module(apptestQml3_6
    URI testQml3_6
    VERSION 1.0
    QML_FILES main.qml 
)


qt_add_lupdate(apptestQml3_6 TS_FILES ${OUR_TS_FILES})
qt_add_lrelease(apptestQml3_6
    TS_FILES ${OUR_TS_FILES}
    QM_FILES_OUTPUT_VARIABLE qm_files)
qt_add_resources(apptestQml3_6 "translations"
    PREFIX "/"
    BASE "${CMAKE_CURRENT_BINARY_DIR}"
    FILES "${QM_FILES}")


set_target_properties(apptestQml3_6 PROPERTIES
    MACOSX_BUNDLE_GUI_IDENTIFIER my.example.com
    MACOSX_BUNDLE_BUNDLE_VERSION ${PROJECT_VERSION}
    MACOSX_BUNDLE_SHORT_VERSION_STRING ${PROJECT_VERSION_MAJOR}.${PROJECT_VERSION_MINOR}
    MACOSX_BUNDLE TRUE
    WIN32_EXECUTABLE TRUE
)

target_link_libraries(apptestQml3_6
    PRIVATE Qt6::Quick)

install(TARGETS apptestQml3_6
    BUNDLE DESTINATION .
    LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR})

要改四个地方
1, 添加 LinguistTools
2，添加ts文件的包含
3，创建ts文件
4，将生成的翻译好的 qm 文件放到资源目录下

项目多执行几次Cmake和构建，不然可能刷新不好。

#include <QGuiApplication>
#include <QQmlApplicationEngine>

#include <QLocale>
#include <QTranslator>

int main(int argc, char *argv[])
{
    QGuiApplication app(argc, argv);

    QTranslator translator;
    const QStringList uiLanguages = QLocale::system().uiLanguages();
    for (const QString &locale : uiLanguages) {
        const QString baseName = "testQml3_6_" + QLocale(locale).name();
//        if (translator.load(":/i18n/" + baseName)) {
//            app.installTranslator(&translator);
//            break;
//        }

        if (translator.load(":/" + baseName)) {
            app.installTranslator(&translator);
            break;
        }

    }

    QQmlApplicationEngine engine;
    const QUrl url(u"qrc:/testQml3_6/main.qml"_qs);
    QObject::connect(&engine, &QQmlApplicationEngine::objectCreated,
                     &app, [url](QObject *obj, const QUrl &objUrl) {
        if (!obj && url == objUrl)
            QCoreApplication::exit(-1);
    }, Qt::QueuedConnection);
    engine.load(url);

    QString t_str = QObject::tr("hello4");

    return app.exec();
}