Qt Linguist - set translator for application Qt *.ui files

问题

I wrote a tiny, simple example to change applications language after choosing a language in menu. Although connect DOES work (qDebug() prints good messages) it doesnt change a text on my QLabel. I created GUI using QtDesigner. NOTE: All of those files are in the same directory. Im using Qt5. Heres my code:

*.pro:

QT       += core gui

greaterThan(QT_MAJOR_VERSION, 4): QT += widgets

TARGET = qt_pl_en
TEMPLATE = app


SOURCES += main.cpp\
        mainwindow.cpp

HEADERS  += mainwindow.h

FORMS    += mainwindow.ui

TRANSLATIONS += ic.ts
TRANSLATIONS += se.ts

mainwindow.cpp

#include "mainwindow.h"
#include "ui_mainwindow.h"

#include <QTranslator>
#include <QDebug>

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);

    retranslate();

    QObject::connect(ui->action_Icelandic, SIGNAL(triggered()), this, SLOT(speakIcelandic()));
    QObject::connect(ui->action_Swedish, SIGNAL(triggered()), this, SLOT(speakSwedish()));
}

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


void MainWindow::changeEvent(QEvent* event)
{
    if (event->type() == QEvent::LanguageChange)
    {
        // retranslate designer form
        ui->retranslateUi(this);

        // retranslate other widgets which weren't added in designer
        retranslate();
    }

    // remember to call base class implementation
    QWidget::changeEvent(event);
}

void MainWindow::retranslate()
{
    ui->label->setText(QObject::tr("Hello, world! :-)"));
}

void MainWindow::speakSwedish()
{
    QTranslator translator;
    translator.load("se.qm");
    qApp->installTranslator(&translator);

    ui->retranslateUi(this);

    qDebug() << "Swedish";
}

void MainWindow::speakIcelandic()
{
    QTranslator translator;
    translator.load("ic.qm");
    qApp->installTranslator(&translator);

    ui->retranslateUi(this);

    qDebug() << "Icelandic";
}

mainwindow.h

    #ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
namespace Ui {
class MainWindow;
}

class MainWindow : public QMainWindow
{
    Q_OBJECT

public:
    explicit MainWindow(QWidget *parent = 0);
    ~MainWindow();

private:
    Ui::MainWindow *ui;

    void retranslate();
    void changeEvent(QEvent* event);


private slots:

    void speakSwedish();
    void speakIcelandic();
};

#endif // MAINWINDOW_H

main.cpp

#include "mainwindow.h"
#include <QApplication>

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    MainWindow w;
    w.show();

    return a.exec();
}

ic.ts

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE TS>
<TS version="2.0" language="en_EN">
<context>
    <name>MainWindow</name>
    <message>
        <location filename="mainwindow.ui" line="14"/>
        <source>MainWindow</source>
        <translation type="unfinished"></translation>
    </message>
    <message>
        <location filename="mainwindow.ui" line="27"/>
        <location filename="mainwindow.cpp" line="13"/>
        <source>Hello, world! :-)</source>
        <translation type="unfinished">Halló, heimur! :-)</translation>
    </message>
    <message>
        <location filename="mainwindow.ui" line="42"/>
        <source>File</source>
        <translation type="unfinished"></translation>
    </message>
    <message>
        <location filename="mainwindow.ui" line="60"/>
        <source>&amp;Swedish</source>
        <translation type="unfinished"></translation>
    </message>
    <message>
        <location filename="mainwindow.ui" line="65"/>
        <source>&amp;Icelandic</source>
        <translation type="unfinished"></translation>
    </message>
</context>
</TS>

se.ts

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE TS>
<TS version="2.0" language="en_EN">
<context>
    <name>MainWindow</name>
    <message>
        <location filename="mainwindow.ui" line="14"/>
        <source>MainWindow</source>
        <translation type="unfinished"></translation>
    </message>
    <message>
        <location filename="mainwindow.ui" line="27"/>
        <location filename="mainwindow.cpp" line="13"/>
        <source>Hello, world! :-)</source>
        <translation type="unfinished">Hallå, världen! :-)</translation>
    </message>
    <message>
        <location filename="mainwindow.ui" line="42"/>
        <source>File</source>
        <translation type="unfinished"></translation>
    </message>
    <message>
        <location filename="mainwindow.ui" line="60"/>
        <source>&amp;Swedish</source>
        <translation type="unfinished"></translation>
    </message>
    <message>
        <location filename="mainwindow.ui" line="65"/>
        <source>&amp;Icelandic</source>
        <translation type="unfinished"></translation>
    </message>
</context>
</TS>

mainwindow.ui

<?xml version="1.0" encoding="UTF-8"?>
<ui version="4.0">
 <class>MainWindow</class>
 <widget class="QMainWindow" name="MainWindow">
  <property name="geometry">
   <rect>
    <x>0</x>
    <y>0</y>
    <width>400</width>
    <height>300</height>
   </rect>
  </property>
  <property name="windowTitle">
   <string>MainWindow</string>
  </property>
  <widget class="QWidget" name="centralWidget">
   <widget class="QLabel" name="label">
    <property name="geometry">
     <rect>
      <x>120</x>
      <y>80</y>
      <width>181</width>
      <height>17</height>
     </rect>
    </property>
    <property name="text">
     <string>Hello, world! :-)</string>
    </property>
   </widget>
  </widget>
  <widget class="QMenuBar" name="menuBar">
   <property name="geometry">
    <rect>
     <x>0</x>
     <y>0</y>
     <width>400</width>
     <height>25</height>
    </rect>
   </property>
   <widget class="QMenu" name="menuFile">
    <property name="title">
     <string>File</string>
    </property>
    <addaction name="action_Swedish"/>
    <addaction name="action_Icelandic"/>
   </widget>
   <addaction name="menuFile"/>
  </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"/>
  <action name="action_Swedish">
   <property name="text">
    <string>&amp;Swedish</string>
   </property>
  </action>
  <action name="action_Icelandic">
   <property name="text">
    <string>&amp;Icelandic</string>
   </property>
  </action>
 </widget>
 <layoutdefault spacing="6" margin="11"/>
 <resources/>
 <connections/>
</ui>

回答1:

this is worked for me.(translate from English to Portuguese)

1) add this to main.cpp

 QApplication app(argc, argv);

//Language Translation
//change the prefered language 
QString locale = "pt" // say i am doing Portuguese language translation
QString file= app.applicationDirPath() +"/translation_"+locale;
QTranslator translator;
bool result=translator.load(file);
if ((locale != "en")  && !result )
{
    QMessageBox msgBox;
    msgBox.setText("Unable to load language translation files");
    msgBox.exec();  
}
app.installTranslator(&translator);

2) Say if you are going to translate the MainWindow.ui

click the Translatable tick box in each and every lable in that MainWindow.ui using QT Designer. (you have nothing to do in the gui other than this)

3) create translation_pt.ts file as mentioned below. Make sure to put classname inside the name tags

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE TS><TS>
	<context>
		<name>MainWindow</name>
		<!-- Dialog Heading -->
		<message>
			<source>Glasses Fitment Details</source>
			<translation>Detalhes de Calibração dos Óculos</translation>
		</message>
		<!-- Fitter -->
		<message>
			<source>Fitter</source>
			<translation>Ajustador</translation>
		</message>
		<message>
			<source>Fitter's Name</source>
			<translation>Nome do Ajustador</translation>
		</message>
   </context>
</TS>

4) add below line to your .pro file

TRANSLATIONS = translation_pt.ts

5) go to qt installation location and run following command

lrelease "location of the .pro file you edited in step 4"

then you will get translation_pt.qm file at that location

6) copy translation_pt.qm file to the location which your binary is running

then automatically your language in your MainWindow.ui would be translated from English to Portuguese

Thanks,

Saman

回答2:

Ok guys, solution is simpler that you can even imagine. Add:

QTranslator *translator;

into mainwindow.h

then, in speakIcelandic() and speakSwedish() (in mainwindow.cpp) just change the implementation code to:

bool ok = translator->load("se.qm");
qDebug("translation %d", ok);
qApp->installTranslator(translator);

ui->retranslateUi(this);

qDebug() << "Swedish";

Dont forget to add translator = new QTranslator(); in constructor, and it will work, finally!

来源：https://stackoverflow.com/questions/17792798/qt-linguist-set-translator-for-application-qt-ui-files

标签

translation

linguistics