三季稻谷

首先将程序中所有字符串放到self.tr()中，例如self.tr(“Files”)

完成这步后用pylupdate4命令生成ts文件

例如：pylupdate4 GoogleTranslate.py -ts GoogleTranslate_zh_CN.ts

生存ts文件后，用Qt Linguist(Qt语言家)打开ts文件，并将所有字符串翻译成目标语言

翻译好后需要用到lrelease命令生成qm文件

例如：lrelease GoogleTranslate_zh_CN.ts

运行这个命令后会生成GoogleTranslate_zh_CN.qm文件，这个文件就是我们需要的语言文件。

最后在程序的main函数中加入如下语句

    locale = QLocale.system().name()
    appTranslator = QTranslator()
    if appTranslator.load("GoogleTranslate_" + locale):
        app.installTranslator(appTranslator)

中文winxp下运行的效果：

ubuntu10.04 英文locale 下运行效果：

Normally, pressing the TAB key changes focus among widgets. However, I would like to use the TAB key for other purposes (e.g. tab completion). To gain control of the TAB key press event, I need to subclass my widget and reimplement the QObject.event() event handler. I don’t need to re-write the entire event handler. I only need to process TAB key press events. I will pass all other events to the default event handler. The example below subclasses the QLineEdit widget and reimplements the event() method. Pressing the TAB key inside this new widget prints out the text “tab pressed” inside a second QLineEdit box.

The Events and Event Filters Trolltech QT documentation has a good explanation of how this works. My example shows how to use Python and PyQt instead of C++.

import sys
from PyQt4.QtCore import *
from PyQt4.QtGui import * 

####################################################################
def main():
    app = QApplication(sys.argv)
    w = MyWindow()
    w.show()
    sys.exit(app.exec_()) 

####################################################################
class MyWindow(QWidget):
    def __init__(self, *args):
        QWidget.__init__(self, *args)

        # create objects
        self.la = QLabel("Press tab in this box:")
        self.le = MyLineEdit()
        self.la2 = QLabel("\nLook here:")
        self.le2 = QLineEdit()

        # layout
        layout = QVBoxLayout()
        layout.addWidget(self.la)
        layout.addWidget(self.le)
        layout.addWidget(self.la2)
        layout.addWidget(self.le2)
        self.setLayout(layout)

        # connections
        self.connect(self.le, SIGNAL("tabPressed"),
                     self.update)

    def update(self):
        newtext = str(self.le2.text()) + "tab pressed "
        self.le2.setText(newtext)

####################################################################
class MyLineEdit(QLineEdit):
    def __init__(self, *args):
        QLineEdit.__init__(self, *args)

    def event(self, event):
        if (event.type()==QEvent.KeyPress) and (event.key()==Qt.Key_Tab):
            self.emit(SIGNAL("tabPressed"))
            return True

        return QLineEdit.event(self, event)

####################################################################
if __name__ == "__main__":
    main()

via:http://www.saltycrane.com/blog/2008/01/how-to-capture-tab-key-press-event-with/

增加了两种语言互译功能，使用上方便了一些：）
更新了按Ctrl+Return（回车）翻译的功能，及多语言支持，在英文环境下界面是英文，中文系统下是中文

#!/usr/bin/python
# -*- coding:utf-8 -*-
# Filename:GoogleTranslate.py

###############################
#  author:lushuchao
#  Thu May 24 2010
###############################

#Update Tue May 25 2010
#add new function press 'Ctrl+Enter' to translate

import sys
from PyQt4.QtCore import *
from PyQt4.QtGui import *
import json
import urllib
import urllib2
#from PyQt4 import QtGui,QtCore

class MainWindow(QMainWindow):
    def __init__(self,parent=None):
        super(MainWindow,self).__init__(parent)
        #上部
        self.lab1=QLabel(self.tr('First Language:'))
        self.Txtyuyan1=MyQTextEdit()
        self.lab2=QLabel(self.tr('Second Language:'))
        self.Txtyuyan2=MyQTextEdit()
        toplayout=QVBoxLayout()
        toplayout.addWidget(self.lab1)
        toplayout.addWidget(self.Txtyuyan1)
        toplayout.addWidget(self.lab2)
        toplayout.addWidget(self.Txtyuyan2)
        #中部
        self.lab3=QLabel(self.tr('Selected Firest Language:'))
        self.yuyan1=QComboBox()
        self.lab4=QLabel(self.tr('Selected Second Language:'))
        self.yuyan2=QComboBox()
        midlayout=QHBoxLayout()
        midlayout.addWidget(self.lab3)
        midlayout.addWidget(self.yuyan1)
        midlayout.addWidget(self.lab4)
        midlayout.addWidget(self.yuyan2)
        lang=sorted(GTranslate.LANG.keys())
        self.yuyan1.addItems(lang)
        self.yuyan1.setCurrentIndex(lang.index('ENGLISH'))
        self.yuyan2.addItems(lang)
        self.yuyan2.setCurrentIndex(lang.index('CHINESE'))
        #下部
        self.yuyan1TOyuyan2=QPushButton(self.tr('First Language ->Second Language'))
        self.yuyan2TOyuyan1=QPushButton(self.tr('Second Language ->First Language'))
        self.chongzhi=QPushButton(self.tr('Reset'))
        self.guanyuQt=QPushButton(self.tr('AboutQt'))
        self.guanyu=QPushButton(self.tr('About'))
        botlayout=QHBoxLayout()
        botlayout.addWidget(self.yuyan1TOyuyan2)
        botlayout.addWidget(self.yuyan2TOyuyan1)
        botlayout.addWidget(self.chongzhi)
        botlayout.addWidget(self.guanyuQt)
        botlayout.addWidget(self.guanyu)
        #整体布局
        mainlayout=QVBoxLayout()
        mainlayout.addLayout(toplayout)
        mainlayout.addLayout(midlayout)
        mainlayout.addLayout(botlayout)
        self.gbox=QGroupBox('')
        self.gbox.setLayout(mainlayout)
        self.setCentralWidget(self.gbox)
        self.Txtyuyan1.setFocus()
        #connections
        self.connect(self.yuyan1TOyuyan2,SIGNAL("clicked()"),self.translate1to2)
        self.connect(self.yuyan2TOyuyan1,SIGNAL("clicked()"),self.translate2to1)
        self.connect(self.chongzhi,SIGNAL("clicked()"),self.reset)
        self.connect(self.guanyuQt,SIGNAL("clicked()"),self.aboutQt)
        self.connect(self.guanyu,SIGNAL("clicked()"),self.showAbout)
        self.connect(self.yuyan1,SIGNAL("currentIndexChanged(int)"),self.setlabtxt)
        self.connect(self.yuyan2,SIGNAL("currentIndexChanged(int)"),self.setlabtxt)
        self.connect(self.Txtyuyan1, SIGNAL("ReturnPressed"),self.translate1to2)
        self.connect(self.Txtyuyan2, SIGNAL("ReturnPressed"),self.translate2to1)
        #初始化
        self.resize(500,300)
        self.center()
        self.setWindowTitle(self.tr('Google Translate Client v1.0'))
        self.setlabtxt()
        self.chongzhi.setEnabled(False)

    def setlabtxt(self):
        f=self.tr('First Language:')
        s=self.tr('Second Language:')
        self.lab1.setText(f+self.yuyan1.currentText())
        self.lab2.setText(s+self.yuyan2.currentText())

    def center(self):
        screen = QDesktopWidget().screenGeometry()
        size =  self.geometry()
        self.move((screen.width()-size.width())/2,
            (screen.height()-size.height())/2) 

#    def keyPressEvent(self, event):
#        key = event.key()
#        if key ==Qt.Key_Return:
#            self.translate()
#            return

    def translate1to2(self):
        text=self.Txtyuyan1.toPlainText()
        text=unicode(text).encode('utf-8')
        key=str(self.yuyan1.currentText())
        langOrigin=GTranslate.LANG[key]
        key=str(self.yuyan2.currentText())
        langTarget=GTranslate.LANG[key]
        self.gt=GTranslate(langOrigin, langTarget, text)
        self.connect(self.gt, SIGNAL("finished()"), self.showResult1to2)

        self.gt.start()
        self.updateUi(False)

    def translate2to1(self):
        text=self.Txtyuyan2.toPlainText()
        text=unicode(text).encode('utf-8')
        key=str(self.yuyan2.currentText())
        langOrigin=GTranslate.LANG[key]
        key=str(self.yuyan1.currentText())
        langTarget=GTranslate.LANG[key]
        self.gt=GTranslate(langOrigin, langTarget, text)
        self.connect(self.gt, SIGNAL("finished()"), self.showResult2to1)

        self.gt.start()
        self.updateUi(False)

    def showResult1to2(self):
        result=self.gt.result
        if(result):
            self.Txtyuyan2.setText(result)
        self.updateUi(True)

    def showResult2to1(self):
        result=self.gt.result
        if(result):
            self.Txtyuyan1.setText(result)
        self.updateUi(True)
    def updateUi(self, enable):
        self.yuyan1TOyuyan2.setEnabled(enable)
        self.yuyan2TOyuyan1.setEnabled(enable)
        self.chongzhi.setEnabled(not enable)

    def reset(self):
        self.gt.terminate()
        self.Txtyuyan1.clear()
        self.Txtyuyan2.clear()
        self.updateUi(True)

    def aboutQt(self):
        self.ab=QMessageBox.aboutQt(self,self.tr('About QT'))

    def showAbout(self):
        dialog = about(self)
        dialog.exec_()

class about(QDialog):
    def __init__(self, parent=None):
        super(about, self).__init__(parent)
        self.setWindowTitle(self.tr('About'))
class MyQTextEdit(QTextEdit):
    def __init__(self, *args):
        QTextEdit.__init__(self, *args)

    def event(self, event):
        if (event.type()==QEvent.KeyPress) and (event.key()==Qt.Key_Return):
                if event.modifiers() & Qt.ControlModifier:
                    self.key = "Ctrl+Return"
                    self.emit(SIGNAL("ReturnPressed"))
                    return True

        return QTextEdit.event(self, event)

class GTranslate(QThread):

    def __init__(self, langOrigin='en', langTarget='zh', text=None, parent=None):
        QThread.__init__(self, parent)

        self.text=text
        self.langOrigin=langOrigin
        self.langTarget=langTarget
        self.result=None

    def translate(self):
        query = (GTranslate.URL % (urllib.quote(self.text), self.langOrigin, self.langTarget))
        req = urllib2.Request(query)
#        req.add_header("Referer", "http://www.my-ajax-site.com")
        try:
            r = urllib2.urlopen(req)
            data = r.read()
        except:
            self.result='Network Connect Error!'
            return

        obj = json.loads(data)
        if obj['responseStatus'] != 200L:
            self.result="Error: %s" % obj['responseDetails']
        else:
            self.result=obj['responseData']['translatedText']

    def run(self):
        self.translate()

    URL = "http://ajax.googleapis.com/ajax/services/language/translate?v=1.0&q=%s&langpair=%s%%7C%s"
    LANG={
       'AFRIKAANS' : 'af',
  'ALBANIAN' : 'sq',
  'AMHARIC' : 'am',
  'ARABIC' : 'ar',
  'ARMENIAN' : 'hy',
  'AZERBAIJANI' : 'az',
  'BASQUE' : 'eu',
  'BELARUSIAN' : 'be',
  'BENGALI' : 'bn',
  'BIHARI' : 'bh',
  'BULGARIAN' : 'bg',
  'BURMESE' : 'my',
  'CATALAN' : 'ca',
  'CHEROKEE' : 'chr',
  'CHINESE' : 'zh',
  'CHINESE_SIMPLIFIED' : 'zh-CN',
  'CHINESE_TRADITIONAL' : 'zh-TW',
  'CROATIAN' : 'hr',
  'CZECH' : 'cs',
  'DANISH' : 'da',
  'DHIVEHI' : 'dv',
  'DUTCH': 'nl',
  'ENGLISH' : 'en',
  'ESPERANTO' : 'eo',
  'ESTONIAN' : 'et',
  'FILIPINO' : 'tl',
  'FINNISH' : 'fi',
  'FRENCH' : 'fr',
  'GALICIAN' : 'gl',
  'GEORGIAN' : 'ka',
  'GERMAN' : 'de',
  'GREEK' : 'el',
  'GUARANI' : 'gn',
  'GUJARATI' : 'gu',
  'HEBREW' : 'iw',
  'HINDI' : 'hi',
  'HUNGARIAN' : 'hu',
  'ICELANDIC' : 'is',
  'INDONESIAN' : 'id',
  'INUKTITUT' : 'iu',
  'ITALIAN' : 'it',
  'JAPANESE' : 'ja',
  'KANNADA' : 'kn',
  'KAZAKH' : 'kk',
  'KHMER' : 'km',
  'KOREAN' : 'ko',
  'KURDISH': 'ku',
  'KYRGYZ': 'ky',
  'LAOTHIAN': 'lo',
  'LATVIAN' : 'lv',
  'LITHUANIAN' : 'lt',
  'MACEDONIAN' : 'mk',
  'MALAY' : 'ms',
  'MALAYALAM' : 'ml',
  'MALTESE' : 'mt',
  'MARATHI' : 'mr',
  'MONGOLIAN' : 'mn',
  'NEPALI' : 'ne',
  'NORWEGIAN' : 'no',
  'ORIYA' : 'or',
  'PASHTO' : 'ps',
  'PERSIAN' : 'fa',
  'POLISH' : 'pl',
  'PORTUGUESE' : 'pt-PT',
  'PUNJABI' : 'pa',
  'ROMANIAN' : 'ro',
  'RUSSIAN' : 'ru',
  'SANSKRIT' : 'sa',
  'SERBIAN' : 'sr',
  'SINDHI' : 'sd',
  'SINHALESE' : 'si',
  'SLOVAK' : 'sk',
  'SLOVENIAN' : 'sl',
  'SPANISH' : 'es',
  'SWAHILI' : 'sw',
  'SWEDISH' : 'sv',
  'TAJIK' : 'tg',
  'TAMIL' : 'ta',
  'TAGALOG' : 'tl',
  'TELUGU' : 'te',
  'THAI' : 'th',
  'TIBETAN' : 'bo',
  'TURKISH' : 'tr',
  'UKRAINIAN' : 'uk',
  'URDU' : 'ur',
  'UZBEK' : 'uz',
  'UIGHUR' : 'ug',
  'VIETNAMESE' : 'vi',
  'UNKNOWN' : ''
    }

def main():
    app=QApplication(sys.argv)
    locale = QLocale.system().name()
    qtTranslator = QTranslator()
    if qtTranslator.load("qt_" + locale):
        app.installTranslator(qtTranslator)
    appTranslator = QTranslator()
    if appTranslator.load("GoogleTranslate_" + locale):
        app.installTranslator(appTranslator)
    app.setOrganizationName("BlueSea Ltd.")
    app.setOrganizationDomain("Thinkman.com.cn")
    #app.setApplicationName(app.translate("MainWindow", "Google Translate Client v1.0"))
    app.setWindowIcon(QIcon("icon.png"))
    form=MainWindow()
    form.show()
    app.exec_()
if __name__=="__main__":
    main()