如何在 PyQt5 上动态更改语言(翻译)? [英] How to change languages(translations) dynamically on PyQt5?

问题描述

我想知道是否可以在不使用 qt 设计器制作 UI 的情况下动态更改语言(翻译)?这意味着我不想使用函数 retranslateUi() 来更新程序界面.

这是我的代码，但我被困在标记为 #1 #2 #3 的行上.不知道我应该用什么来更新界面.

导入系统从 PyQt5.QtCore 导入 Qt，QTranslator从 PyQt5.QtWidgets 导入 QApplication、QWidget、QPushButton、QLabel，QComboBox, QVBoxLayout类演示(QWidget):def __init__(self):super(Demo, self).__init__()self.button = QPushButton(self.tr('Start'), self)self.label = QLabel(self.tr('Hello, World'), self)self.label.setAlignment(Qt.AlignCenter)self.combo = QComboBox(self)self.combo.addItem('英文')self.combo.addItem('中文')self.combo.addItem('法语')self.combo.currentTextChanged.connect(self.change_func)self.trans = QTranslator(self)self.v_layout = QVBoxLayout()self.v_layout.addWidget(self.combo)self.v_layout.addWidget(self.button)self.v_layout.addWidget(self.label)self.setLayout(self.v_layout)def change_func(self):打印(self.combo.currentText())如果 self.combo.currentText() == '中文':self.trans.load('eng-chs')_app = QApplication.instance()_app.installTranslator(self.trans)#1elif self.combo.currentText() == '法语':self.trans.load('eng-fr')_app = QApplication.instance()_app.installTranslator(self.trans)# 2别的:_app = QApplication.instance()_app.removeTranslator(self.trans)# 3如果 __name__ == '__main__':app = QApplication(sys.argv)演示 = 演示()演示.show()sys.exit(app.exec_())

任何帮助将不胜感激.

解决方案

TL;DR;没必要用Qt Designer

---

您不一定要使用 Qt Designer，但您应该使用相同的技术，即创建一个可以称为 retranslateUi() 的方法，并在其中使用 translate() 而不是 tr()(有关更多详细信息，请阅读

_{您可以在此处找到完整的项目.}

I wonder if it is possible to change the languages(translations) dynamically without using qt designer to make the UI? That means I don't want to use the function retranslateUi() to update the program interface.

Here is my code, but I'm stuck on lines marked #1 #2 #3. Don't know what I should use to update the interface.

import sys
from PyQt5.QtCore import Qt, QTranslator
from PyQt5.QtWidgets import QApplication, QWidget, QPushButton, QLabel, 
QComboBox, QVBoxLayout


class Demo(QWidget):
    def __init__(self):
        super(Demo, self).__init__()
        self.button = QPushButton(self.tr('Start'), self)
        self.label = QLabel(self.tr('Hello, World'), self)
        self.label.setAlignment(Qt.AlignCenter)

        self.combo = QComboBox(self)
        self.combo.addItem('English')
        self.combo.addItem('中文')
        self.combo.addItem('français')
        self.combo.currentTextChanged.connect(self.change_func)

        self.trans = QTranslator(self)

        self.v_layout = QVBoxLayout()
        self.v_layout.addWidget(self.combo)
        self.v_layout.addWidget(self.button)
        self.v_layout.addWidget(self.label)
        self.setLayout(self.v_layout)

    def change_func(self):
        print(self.combo.currentText())
        if self.combo.currentText() == '中文':
            self.trans.load('eng-chs')
            _app = QApplication.instance()
            _app.installTranslator(self.trans)
            # 1

        elif self.combo.currentText() == 'français':
            self.trans.load('eng-fr')
            _app = QApplication.instance()
            _app.installTranslator(self.trans)
            # 2

        else:
            _app = QApplication.instance()
            _app.removeTranslator(self.trans) 
             # 3


if __name__ == '__main__':
    app = QApplication(sys.argv)
    demo = Demo()
    demo.show()
    sys.exit(app.exec_())

Any help would be appreciated.

解决方案

TL; DR; It is not necessary to use Qt Designer

---

You should not use Qt Designer necessarily but you should use the same technique, that is, create a method that could be called retranslateUi() and in it set the texts using translate() instead of tr() (for more details read the docs). Calling that method when you change language for it must use the changeEvent() event. For example in your case the code is as follows:

import sys
from PyQt5 import QtCore, QtGui, QtWidgets

class Demo(QtWidgets.QWidget):
    def __init__(self):
        super(Demo, self).__init__()
        self.button = QtWidgets.QPushButton()
        self.label = QtWidgets.QLabel(alignment=QtCore.Qt.AlignCenter)

        self.combo = QtWidgets.QComboBox(self)
        self.combo.currentIndexChanged.connect(self.change_func)

        self.trans = QtCore.QTranslator(self)

        self.v_layout = QtWidgets.QVBoxLayout(self)
        self.v_layout.addWidget(self.combo)
        self.v_layout.addWidget(self.button)
        self.v_layout.addWidget(self.label)

        options = ([('English', ''), ('français', 'eng-fr' ), ('中文', 'eng-chs'), ])
        
        for i, (text, lang) in enumerate(options):
            self.combo.addItem(text)
            self.combo.setItemData(i, lang)
        self.retranslateUi()

    @QtCore.pyqtSlot(int)
    def change_func(self, index):
        data = self.combo.itemData(index)
        if data:
            self.trans.load(data)
            QtWidgets.QApplication.instance().installTranslator(self.trans)
        else:
            QtWidgets.QApplication.instance().removeTranslator(self.trans)

    def changeEvent(self, event):
        if event.type() == QtCore.QEvent.LanguageChange:
            self.retranslateUi()
        super(Demo, self).changeEvent(event)

    def retranslateUi(self):
        self.button.setText(QtWidgets.QApplication.translate('Demo', 'Start'))
        self.label.setText(QtWidgets.QApplication.translate('Demo', 'Hello, World'))

if __name__ == '__main__':
    app = QtWidgets.QApplication(sys.argv)
    demo = Demo()
    demo.show()
    sys.exit(app.exec_())

Then generate the .ts:

pylupdate5 main.py  -ts eng-chs.ts
pylupdate5 main.py  -ts eng-fr.ts

Then use Qt Linguist to do the translations.

And finally the .qm:

lrelease eng-fr.ts eng-chs.qm

_{The complete project you find here.}

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