内容

• 公共函数
• 详细描述
• 查找翻译
• Using Multiple Translations

QTranslator 类

QTranslator class provides internationalization support for text output. 更多...

头：	#include <QTranslator>
qmake:	QT += core
继承：	QObject

• 所有成员列表，包括继承成员

公共函数

	QTranslator (QObject * parent = Q_NULLPTR)
	~QTranslator ()
virtual bool	isEmpty () const
bool	load (const QString & filename , const QString & directory = QString(), const QString & search_delimiters = QString(), const QString & suffix = QString())
bool	load (const QLocale & locale , const QString & filename , const QString & prefix = QString(), const QString & directory = QString(), const QString & suffix = QString())
bool	load (const uchar * data , int len , const QString & directory = QString())
virtual QString	translate (const char * context , const char * sourceText , const char * disambiguation = Q_NULLPTR, int n = -1) const

• 32 公共函数继承自 QObject

额外继承成员

• 1 特性继承自 QObject
• 1 公共槽继承自 QObject
• 2 信号继承自 QObject
• 11 静态公共成员继承自 QObject
• 9 保护函数继承自 QObject

详细描述

QTranslator class provides internationalization support for text output.

An object of this class contains a set of translations from a source language to a target language. QTranslator provides functions to look up translations in a translation file. Translation files are created using Qt Linguist .

The most common use of QTranslator is to: load a translation file, install it using QCoreApplication::installTranslator (), and use it via QObject::tr (). Here's an example main() function using the QTranslator :

int main(int argc, char *argv[])
{
    QApplication app(argc, argv);
    QTranslator translator;
    // look up e.g. :/translations/myapp_de.qm
    if (translator.load(QLocale(), QLatin1String("myapp"), QLatin1String("_"), QLatin1String(":/translations")))
        app.installTranslator(&translator);
    QPushButton hello(QCoreApplication::translate("main", "Hello world!"));
    hello.resize(100, 30);
    hello.show();
    return app.exec();
}
					

注意：翻译器必须被创建 before 应用程序的 Widget。

Most applications will never need to do anything else with this class. The other functions provided by this class are useful for applications that work on translator files.

查找翻译

它是可能的，查找翻译使用 translate () (作为 tr () 和 QCoreApplication::translate () 做的)。 translate () 函数最多接受 3 参数：

• context - 通常是类名对于 tr () 调用者。
• 源文本 - usually the argument to tr ().
• disambiguation - an optional string that helps disambiguate different uses of the same text in the same context.

For example, the "Cancel" in a dialog might have "Anuluj" when the program runs in Polish (in this case the source text would be "Cancel"). The context would (normally) be the dialog's class name; there would normally be no comment, and the translated text would be "Anuluj".

But it's not always so simple. The Spanish version of a printer dialog with settings for two-sided printing and binding would probably require both "Activado" and "Activada" as translations for "Enabled". In this case the source text would be "Enabled" in both cases, and the context would be the dialog's class name, but the two items would have disambiguations such as "two-sided printing" for one and "binding" for the other. The disambiguation enables the translator to choose the appropriate gender for the Spanish version, and enables Qt to distinguish between translations.

Using Multiple Translations

Multiple translation files can be installed in an application. Translations are searched for in the reverse order in which they were installed, so the most recently installed translation file is searched for translations first and the earliest translation file is searched last. The search stops as soon as a translation containing a matching string is found.

This mechanism makes it possible for a specific translation to be "selected" or given priority over the others; simply uninstall the translator from the application by passing it to the QCoreApplication::removeTranslator () function and reinstall it with QCoreApplication::installTranslator (). It will then be the first translation to be searched for matching strings.

另请参阅 QCoreApplication::installTranslator (), QCoreApplication::removeTranslator (), QObject::tr (), QCoreApplication::translate (), I18N 范例 , Hello tr () 范例， Arrow Pad Example ，和 Troll Print Example .

成员函数文档编制

QTranslator:: QTranslator ( QObject * parent = Q_NULLPTR)

构造空的消息文件对象采用父级 parent 未连接到任何文件。

QTranslator:: ~QTranslator ()

销毁对象并释放任何分配资源。

[virtual] bool QTranslator:: isEmpty () const

返回 true 若此翻译器为空，否则返回 false 。此函数处理剥离和未剥离翻译文件。

bool QTranslator:: load (const QString & filename , const QString & directory = QString(), const QString & search_delimiters = QString(), const QString & suffix = QString())

加载 filename + suffix (.qm 若 suffix 未指定)，可能是绝对文件名或相对于 directory 。返回 true 若成功加载翻译；否则返回 false .

若 directory is not specified, the current directory is used (i.e., as currentPath() ).

将丢弃此翻译器对象的先前内容。

若文件名不存在，则按以下次序尝试其它文件名：

1. 文件名不带 suffix 追加。
2. File name with text after a character in search_delimiters stripped ("_." is the default for search_delimiters if it is an empty string) and suffix .
3. File name stripped without suffix 追加。
4. File name stripped further, etc.

For example, an application running in the fr_CA locale (French-speaking Canada) might call load("foo.fr_ca", "/opt/foolib"). load() would then try to open the first existing readable file from this list:

1. /opt/foolib/foo.fr_ca.qm
2. /opt/foolib/foo.fr_ca
3. /opt/foolib/foo.fr.qm
4. /opt/foolib/foo.fr
5. /opt/foolib/foo.qm
6. /opt/foolib/foo

Usually, it is better to use the QTranslator::load(const QLocale &, const QString &, const QString &, const QString &, const QString &) function instead, because it uses QLocale::uiLanguages () and not simply the locale name, which refers to the formatting of dates and numbers and not necessarily the UI language.

bool QTranslator:: load (const QLocale & locale , const QString & filename , const QString & prefix = QString(), const QString & directory = QString(), const QString & suffix = QString())

加载 filename + prefix + ui language name + suffix (.qm 若 suffix 未指定)，可能是绝对文件名或相对于 directory 。返回 true 若成功加载翻译；否则返回 false .

将丢弃此翻译器对象的先前内容。

若文件名不存在，则按以下次序尝试其它文件名：

1. 文件名不带 suffix 追加。
2. File name with ui language part after a "_" character stripped and suffix .
3. File name with ui language part stripped without suffix 追加。
4. File name with ui language part stripped further, etc.

例如，应用程序运行在 locale 采用下列 UI 语言 - "es", "fr-CA", "de" might call load(QLocale(), "foo", ".", "/opt/foolib", ".qm"). load () would replace '-' (dash) with '_' (underscore) in the ui language and then try to open the first existing readable file from this list:

1. /opt/foolib/foo.es.qm
2. /opt/foolib/foo.es
3. /opt/foolib/foo.fr_CA.qm
4. /opt/foolib/foo.fr_CA
5. /opt/foolib/foo.de.qm
6. /opt/foolib/foo.de
7. /opt/foolib/foo.fr.qm
8. /opt/foolib/foo.fr
9. /opt/foolib/foo.qm
10. /opt/foolib/foo .
11. /opt/foolib/foo

在文件系统区分大小写的操作系统， QTranslator 还会试着加载区域设置名称的小写版本。

该函数在 Qt 4.8 引入。

bool QTranslator:: load (const uchar * data , int len , const QString & directory = QString())

此函数重载 load ().

加载 QM 文件数据 data 的长度 len 进翻译者。

The data is not copied. The caller must be able to guarantee that data will not be deleted or modified.

directory is only used to specify the base directory when loading the dependencies of a QM file. If the file does not have dependencies, this argument is ignored.

[virtual] QString QTranslator:: translate (const char * context , const char * sourceText , const char * disambiguation = Q_NULLPTR, int n = -1) const

返回翻译对于键 ( context , sourceText , disambiguation )。若未找到，还会尝试 ( context , sourceText , "")。若仍失败，返回 null 字符串。

注意： Incomplete translations may result in unexpected behavior: If no translation for ( context , sourceText , "") is provided, the method might in this case actually return a translation for a different disambiguation .

若 n is not -1, it is used to choose an appropriate form for the translation (e.g. "%n file found" vs. "%n files found").

If you need to programatically insert translations into a QTranslator ，此函数可以被重实现。

另请参阅 load ().