Unicode is the standard for encoding text in almost all languages spoken in the world. It is nowadays used as the native encoding for text on most modern operating systems. The major exception is Microsoft Windows that still has a dual system supporting code pages and Unicode for applications.
These classes are relevant when working with string data. For information about rendering text, see the 富文本处理 overview, and if your string data is in XML, see the XML 处理 概述。
QAnyStringView | 带有 QString API 只读子集的 Latin-1、UTF-8 或 UTF-16 字符串统一视图 |
QByteArray | 字节数组 |
QByteArrayList | 字节数组列表 |
QByteArrayMatcher | 保持在字节数组中可以快速匹配的字节序列 |
QByteArrayView | 带有只读 QByteArray API 子集的字节数组视图 |
QChar | 16 位 Unicode 字符 |
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 |
QLatin1Char | 8 位 ASCII/Latin-1 字符 |
QLatin1String | 围绕 US-ASCII/Latin-1 编码字符串文字的瘦包裹器 |
QLocale | 在数字及其各种语言的字符串表示之间转换 |
QStaticByteArrayMatcher | QByteArrayMatcher 的编译时版本 |
QString | Unicode 字符串 |
QStringList | 字符串列表 |
QStringMatcher | 保持可以在 Unicode 字符串中快速匹配的字符序列 |
QStringRef | 围绕 QString 子字符串的瘦包裹器 |
QStringTokenizer | 沿给定分隔符将字符串分割成令牌 |
QStringView | 带有 QString API 只读子集的 UTF-16 字符串统一视图 |
QTextBoundaryFinder | 在字符串中查找 Unicode 文本边界的办法 |
QTextStream | 用于读写文本的方便接口 |
QUtf8StringView | 带有 QString API 只读子集的 UTF-8 字符串统一视图 |
Unicode Consortium has a number of documents available, including
In Qt, and in most applications that use Qt, most or all user-visible strings are stored using Unicode. Qt provides:
To fully benefit from Unicode, we recommend using QString for storing all user-visible strings, and performing all text file I/O using QTextStream .
All the function arguments in Qt that may be user-visible strings,
QLabel::setText
() and a many others, take
const QString &
s.
QString
provides implicit casting from
const char *
so that things like
label->setText("Password:");
will work. There is also a function, QObject::tr (), that provides translation support, like this:
label->setText(tr("Password:"));
QObject::tr
() maps from
const char *
to a Unicode string, and uses installable
QTranslator
objects to do the mapping.
Qt provides a number of built-in QTextCodec classes, that is, classes that know how to translate between Unicode and legacy encodings to support programs that must talk to other programs or read/write files in legacy file formats.
Conversion to/from
const char *
uses a UTF-8. However, applications can easily find codecs for other locales, and set any open file or network connection to use a special codec.
Since US-ASCII and ISO-8859-1 are so common, there are also especially fast functions for mapping to and from them. For example, to open an application's icon one might do this:
QFile file(QString::fromLatin1("appicon.png"));
or
QFile file(QLatin1String("appicon.png"));
Qt supports rendering text in most languages written in the world. The detailed list of supported writing systems depends a bit on operating system support and font availability on the target system.
另请参阅 Qt 国际化 .