The 国际化 and 本地化 对于应用程序是使应用程序适配不同语言、地区差异及目标市场技术要求的过程。
国际化需要的范围从拼写改变到使应用程序能以不同语言运转，和使用不同输入技术、字符编码及表示约定。
Qt 中的所有输入控件和文本绘制方法，有为所有支持语言提供内置支持。内置字体引擎可以正确渲染，同时包含来自各种不同书写系统字符的文本。
| 了解更多有关信息 | 见 |
|---|---|
| 国际化源代码 | 编写翻译源代码 |
| 配置和部署翻译，及使用现有 Qt 模块翻译 | 本地化应用程序 |
| 使用 Qt 翻译工具 | Qt Linguist 手册 |
以下视频展示如何国际化和本地化简单范例应用程序：
下列类支持 Qt 应用程序的国际化。
| QCollator | 根据本地整理算法比较字符串 |
| QCollatorSortKey | 可以用于加速字符串整理 |
| QLocale | 在数字及其各种语言的字符串表示之间转换 |
| QStringConverter | 用于编码和解码文本的基类 |
| QStringDecoder | 用于文本基于状态的解码器 |
| QStringEncoder | 用于文本基于状态的编码器 |
| QTextCodec | 在文本编码间转换 |
| QTextDecoder | 基于状态的解码器 |
| QTextEncoder | 基于状态的编码器 |
| QTranslator | 用于文本输出的国际化支持 |
见 编写翻译源代码 了解如何在应用程序中使用类的更多有关信息。
Qt 支持大多数 languages 今天在使用。
输入控件，譬如 Qt Quick TextInput 类型和 QLineEdit , QTextEdit ，和派生类，及显示控件，譬如 Text 类型和 QLabel 类处理下列不同书写系统的特殊特征：
Some of the Asian languages are written without spaces between words. Line breaking can occur either after any character (with exceptions) as in Chinese, Japanese and Korean, or after logical word boundaries as in Thai.
Arabic and Hebrew are written from right to left, except for numbers and embedded English text which is written left to right. The exact behavior is defined in the Unicode Technical Annex #9 .
Some languages, such as Vietnamese, make extensive use of these marks and some characters can have more than one mark at the same time to clarify pronunciation.
In special contexts, some pairs of characters get replaced by a combined glyph forming a ligature. Common examples are the
fl
and
fi
ligatures used in typesetting US and European books.
Qt 文本引擎 支持不同 书写系统 that work on all platforms if the fonts for rendering them are installed.
You do not need to know about the writing system used in a particular language, unless you want to write your own text input controls. In some languages, such as Arabic or languages from the Indian subcontinent, the width and shape of a glyph changes depending on the surrounding characters. To take this into account in C++ code, use QTextLayout . Writing input controls also requires some knowledge of the scripts they are going to be used in. Usually, the easiest way is to subclass QLineEdit or QTextEdit .
编码与应用程序源文件和应用程序读取 (或写入) 的文本文件两者相关。
QML documents are always encoded in UTF-8 format. Since Qt 6, 8-bit UTF-8 is the predominant encoding also in Qt C++.
The
lupdate
tool extracts UI strings from your application. It expects all source code to be encoded in UTF-8 by default.
However, some editors, such as Visual Studio, use a different encoding by default. One way to avoid encoding issues is to limit any source code to ASCII, and use escape sequences for translatable strings with other characters, for example:
label->setText(tr("F\374r \310lise"));
QString::toUtf8
() returns the text in UTF-8 encoding, which preserves
Unicode
information while looking like plain ASCII if the text is wholly ASCII. To convert Unicode to local 8-bit encoding, use
QString::toLocal8Bit
(). On Unix systems, this is equivalent to
toUtf8()
. On Windows, the system's current code page is used.
For converting from UTF-8 and local 8-bit encoding to QString ，使用 QString::fromUtf8 () 和 QString::fromLocal8Bit () convenience functions.
使用 QTextStream::setEncoding () to set common encoding for text streams.
If you need some other legacy encoding, use the QTextCodec class from the Qt5Compat module.
When an application starts, the locale of the machine determines the 8-bit encoding used for external 8-bit data. QTextCodec::codecForLocale () returns a codec that you can use to convert between this locale encoding and Unicode.
The application may occasionally require encoding other than the default local 8-bit encoding. For example, an application in a Cyrillic KOI8-R locale (the de-facto standard locale in Russia) might need to output Cyrillic in the ISO 8859-5 encoding. Code for this would be:
QString string = ...; // some Unicode text QTextCodec *codec = QTextCodec::codecForName("ISO 8859-5"); QByteArray encodedString = codec->fromUnicode(string);
The following code demonstrates the conversion from ISO 8859-5 Cyrillic to Unicode:
QByteArray encodedString = ...; // some ISO 8859-5 encoded text QTextCodec *codec = QTextCodec::codecForName("ISO 8859-5"); QString string = codec->toUnicode(encodedString);
For a complete list of supported encodings see the QTextCodec 文档编制。
Some of the operating systems and windowing systems that Qt runs on only have limited support for Unicode. The level of support available in the underlying system has some influence on the support that Qt can provide on those platforms, although in general Qt applications need not be too concerned with platform-specific limitations.
/usr/share/locale/ja_JP.EUC
directory, you cannot display Japanese text unless you install Japanese fonts and the directory is complete. For best results, use complete locales from your system vendor.
| 本地化应用程序 | 将 Qt 和 Qt Quick APP 本地化成多种语言。 |
| Qt Linguist 范例 | 使用 Qt Linguist 国际化 Qt 应用程序 |
| Qt Linguist 手册 | Using Qt translation tools: lupdate, lrelease, and Qt Linguist |
| 基于文本 ID 的翻译 | Text ID based internationalization provides support for large scale projects with many target locales and many texts to translate |
| 复数形式翻译规则 | A summary of the translation rules for plural forms produced by Qt's translation tools. |
| 编写翻译源代码 | Writing source code that enables the localization of applications. |