Qt自带翻译无效

Qt自带翻译无效

问题：在使用 QMessageBox 时，Qt 标准按钮没有被翻译

QMessageBox::information(nullptr, tr("tips"), tr("Are yue sure?"), QMessageBox::Yes);

如上代码，使用了标准按钮 QMessageBox::Yes。因此需要将 qt 翻译加载到程序中

解决方法

1. 加载 Qt 翻译

   • QLibraryInfo
     • 通过 QLibraryInfo 可以获取 Qt 指定的翻译目录，QLibrary 支持目录包括如下：

   onstant	Value	Description
   LibraryInfo::PrefixPath	0	The default prefix for all paths.
   ibraryInfo::DocumentationPath	1	The location for documentation upon install.
   ibraryInfo::HeadersPath	2	The location for all headers.
   ibraryInfo::LibrariesPath	3	The location of installed libraries.
   ibraryInfo::LibraryExecutablesPath	4	The location of installed executables required by libraries at runtime.
   ibraryInfo::BinariesPath	5	The location of installed Qt binaries (tools and applications).
   ibraryInfo::PluginsPath	6	The location of installed Qt plugins.
   ibraryInfo::ImportsPath	7	The location of installed QML extensions to import (QML 1.x).
   ibraryInfo::Qml2ImportsPath	8	The location of installed QML extensions to import (QML 2.x).
   ibraryInfo::ArchDataPath	9	The location of general architecture-dependent Qt data.
   ibraryInfo::DataPath	10	The location of general architecture-independent Qt data.
   ibraryInfo::TranslationsPath	11	The location of translation information for Qt strings.
   ibraryInfo::ExamplesPath	12	The location for examples upon install.
   ibraryInfo::TestsPath	13	The location of installed Qt testcases.
   ibraryInfo::SettingsPath	100	The location for Qt settings. Not applicable on Windows.

   通过 QLibraryInfo::location(QLibraryInfo::TranslationsPath) 可以获取到指定的翻译目录。

   2. QLibraryInfo支持的目录可通过 qt.conf 修改，支持值如下：

Entry	Default Value
Prefix	QCoreApplication::applicationDirPath()
Documentation	doc
Headers	include
Libraries	lib
LibraryExecutables	libexec
Binaries	bin
Plugins	plugins
Imports	imports
Qml2Imports	qml
ArchData	.
Data	.
Translations	translations
Examples	examples
Tests	tests
Settings	.

qt.conf 默认使用资源系统中的 :/qt/etc/qt.conf，没有就依次加载当前目录 和 qt目录

[Paths]
Documentation=../../Docs/Qt-5.11.2
Examples=../../Examples/Qt-5.11.2
Prefix=..

• 当 Qt 翻译都加载正确后， QMessage button依然没有被翻译
  Qt源码：

    QString QPlatformTheme::defaultStandardButtonText(int button)
    {
        switch (button) {
        case QPlatformDialogHelper::Ok:
            return QCoreApplication::translate("QPlatformTheme", "OK");
        case QPlatformDialogHelper::Save:
            return QCoreApplication::translate("QPlatformTheme", "Save");
        case QPlatformDialogHelper::SaveAll:
            return QCoreApplication::translate("QPlatformTheme", "Save All");
        case QPlatformDialogHelper::Open:
            return QCoreApplication::translate("QPlatformTheme", "Open");
        case QPlatformDialogHelper::Yes:
            return QCoreApplication::translate("QPlatformTheme", "&Yes");
        case QPlatformDialogHelper::YesToAll:
            return QCoreApplication::translate("QPlatformTheme", "Yes to &All");
        case QPlatformDialogHelper::No:
            return QCoreApplication::translate("QPlatformTheme", "&No");
        case QPlatformDialogHelper::NoToAll:
            return QCoreApplication::translate("QPlatformTheme", "N&o to All");
        case QPlatformDialogHelper::Abort:
            return QCoreApplication::translate("QPlatformTheme", "Abort");
        case QPlatformDialogHelper::Retry:
            return QCoreApplication::translate("QPlatformTheme", "Retry");
        case QPlatformDialogHelper::Ignore:
            return QCoreApplication::translate("QPlatformTheme", "Ignore");
        case QPlatformDialogHelper::Close:
            return QCoreApplication::translate("QPlatformTheme", "Close");
        case QPlatformDialogHelper::Cancel:
            return QCoreApplication::translate("QPlatformTheme", "Cancel");
        case QPlatformDialogHelper::Discard:
            return QCoreApplication::translate("QPlatformTheme", "Discard");
        case QPlatformDialogHelper::Help:
            return QCoreApplication::translate("QPlatformTheme", "Help");
        case QPlatformDialogHelper::Apply:
            return QCoreApplication::translate("QPlatformTheme", "Apply");
        case QPlatformDialogHelper::Reset:
            return QCoreApplication::translate("QPlatformTheme", "Reset");
        case QPlatformDialogHelper::RestoreDefaults:
            return QCoreApplication::translate("QPlatformTheme", "Restore Defaults");
        default:
            break;
        }
        return QString();
    }
  

我们发现 button 的文本上下文是 QPlatformTheme, 而不是 qt_zh_CN.qm 中 QDialogButtonBox

因此需要通过修改qt_zh_CN.ts，然后生成 qm, 如下图