QT5模板庫(一)

字符串類

操作字符串

basic

QString str1 = "a";
QString str2 = "b";
QString str = str1 + str2;

append

QString str1 = "Welcome";
QString str2 = "to";
str1.append(str2);
str1.append(" you! ");

sprintf

Qstring str;
str.sprintf("%s", "Welcome");
str.sprintf("%s %s", "Welcome","to you");

%n

QString str;
str=QString("%1 was born in %2.").arg("Bob").arg(1998);

others

insert() 特定位置插入字符串
prepend() 開頭插入字符串
replace() 指定字符串代替原字符串
QString::trimmed() 移除字符串兩端的空白字符
QString::simplified() 一處字符串兩端空白字符 使用單個空格字符代替

查詢字符串

QString::startsWith() QString::endsWith()

QString  str = "Aa Bb Cc";
str.startsWith("Aa",Qt::CaseSensitive); //true
str.startsWith("Bb",Qt::CaseSensitive); //false

QString::contains()

QString  str = "Aa Bb Cc";
str.startsWith("Bb",Qt::CaseSensitive); //true

operator<(const QString &)

operator<=(const QString &)

…

字符串轉換

QString::toInt(); QString::toDouble(); QString::toFloat(); QString::toLong(); QString::toLongLong();

QString str = "125";
bool ok;
int hex = str.toInt(&ok,16); // ok = True, hex = 293
int dec = str.toInt(&ok,10); // ok = True, dec=125

toAscii()

toLatin1()

toUtf8()

toLocal8Bit()

isNull()

isEmpty()

容器類

#include <QDebug>
int main(){
    QList<QString> list;
    {
        QString str("abc");
        list<<str;
    }
    qDebug()<<list[0]<<"What";
    return 0;
}

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