是否可以重新翻译（tr）QString const？

Question

我有这个挑战。我试图避免#define NEW_LABEL "---New label---"。

我想通过define class constant以正确的方式进行操作。

myclass.h

class MyClass:public QDialog{ 
private:
Ui::MyClassWidget* ui;
const QString NEW_LABEL_TEXT;
}

myclass.cpp

//const init

MyClass::MyClass():ui(new Ui::MyClassWidget),NEW_LABEL_TEXT(tr("---New label---")){
some stuff..
}

我的问题是：

当我想重新翻译成其他语言时，这是正确的方法吗？ QString const 可以动态重新翻译吗？

空中交通管制

感谢您的回答和提示。

Answer 1

在QWidget派生类中，如QDialog，可以监听翻译语言变化。

class MyDialog : public QDialog {
protected:
  virtual void changedEvent(QEvent * event) override {
         if (event->type() == QEvent::LanguageChange) {
             /* call tr again here */
             /* for ui object just call retranslateUi to automatically update translations */
             ui->retranslateUi(this);
          }

          QDialog::changedEvent(e);
   }
};

因此，您可以在每次语言更改时在运行时重新翻译一个字符串，但您不能将结果存储在 const QString 中，如果您想要此翻译的类范围，只需将结果存储在静态 QString 中。

Answer 2

您需要保持字符串常量未翻译。但是用QT_TR_NOOP() 标记它，以便语言学家可以看到它，并将其存储为普通的char const*。

然后当你开始实际使用它时，像往常一样翻译它，用你班级的QApplication::translate，或tr()：

// MyClass: Hello! -> Dobrý deň
static const uchar translations[] = {
  60, 184, 100,  24, 202, 239, 156, 149, 205,  33,  28, 191,  96, 161, 189, 221,
  66,   0,   0,   0,   8,   4, 236,  51,  17,   0,   0,   0,   0, 105,   0,   0,
   0,  52,   3,   0,   0,   0,  18,   0,  68,   0, 111,   0,  98,   0, 114,   0,
 253,   0,  32,   0, 100,   0, 101,   1,  72,   8,   0,   0,   0,   0,   6,   0,
   0,   0,   6,  72, 101, 108, 108, 111,  33,   7,   0,   0,   0,   7,  77, 121,
  67, 108,  97, 115, 115,   1,  47,   0,   0,   1,  58,   0, 151,   0,   0,   0,
   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
   0,   0,   0,   0,   0,   0,   1,   0,   0,   0,   0,   0,   0,   0,   0,   0,
   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   7,  77, 121,
  67, 108,  97, 115, 115, 136,   0,   0,   0,   6,   1,   1, 255,   4,   2,   4,
};

#include <QCoreApplication>
#include <QDebug>
#include <QString>
#include <QTranslator>

int main(int argc, char **argv)
{
    static const char *const message = QT_TR_NOOP("Hello!");

    QCoreApplication app{argc, argv};
    QTranslator translator;
    if (!translator.load(translations, sizeof translations))
        qFatal("Failed to load translations");
    app.installTranslator(&translator);

    qInfo() << app.translate("MyClass", message);
    // or tr(message) in your own MyClass object
}