QString较少用到的接口

QString QString::trimmed() const

QString str = "  lots\t of\nwhitespace\r\n ";
str = str.trimmed();
// str == "lots\t of\nwhitespace"

QString str = "  lots\t of\nwhitespace\r\n ";
str = str.simplified();
// str == "lots of whitespace";

QStringList QString::split(const QString &sep, 
                           QString::SplitBehavior behavior = KeepEmptyParts, 
                           Qt::CaseSensitivity cs = Qt::CaseSensitive) const

QString str = "a,,b,c";

QStringList list1 = str.split(',');
// list1: [ "a", "", "b", "c" ]

QStringList list2 = str.split(',', QString::SkipEmptyParts);
// list2: [ "a", "b", "c" ]

QString QStringList::join(const QString &separator) const

void QString::truncate(int position)

QString str = "Hello world";
str.truncate(5);
// str == "Hello"

int QString::count(QChar ch, 
                   Qt::CaseSensitivity cs = Qt::CaseSensitive) const