//! [0]
QByteArray encodedString = "...";
QTextCodec *codec = QTextCodec::codecForName("KOI8-R");
QString string = codec->toUnicode(encodedString);
//! [0]


//! [1]
QString string = "...";
QTextCodec *codec = QTextCodec::codecForName("KOI8-R");
QByteArray encodedString = codec->fromUnicode(string);
//! [1]


//! [2]
QTextCodec *codec = QTextCodec::codecForName("Shift-JIS");
QTextDecoder *decoder = codec->makeDecoder();

QString string;
while (new_data_available()) {
    QByteArray chunk = get_new_data();
    string += decoder->toUnicode(chunk);
}
//! [2]


//! [3]
int main(int argc, char *argv[])
{
    QApplication app(argc, argv);
    QTextCodec::setCodecForTr(QTextCodec::codecForName("eucKR"));
    ...
}
//! [3]