QT QStringList 与 QString 常用方法

ゝ一世哀愁。 2023-02-12 08:26 9阅读 0赞

### QStringList 转 QString ###

QStringList listemp;
    listemp << "Apple" << "Grape" << "Orange" << "Banana";
    QString str = listemp.join(",");
    qDebug() << "\r\nstr:" << str;
    //输出结果如下
    //str: "Apple,Grape,Orange,Banana"

### QString转 QStringList ###

QString strtmp = "apple:5.99;grape:12.5;orange:6.99";
    QStringList fruits = strtmp.split(";");
    qDebug() << "\r\nfruits:" << fruits;
    //fruits: ("apple:5.99", "grape:12.5", "orange:6.99")
    
    //
    for(int i=0; i < fruits.size(); i++)
    { 
        QStringList fruit = fruits[i].split((":"));
        qDebug() << "fruit:" << fruit;
        /* fruit: ("apple", "5.99") fruit: ("grape", "12.5") fruit: ("orange", "6.99") */
    }

### QStringList 其他常用方法 ###

//使用QStringList拆分QString
    QString str = "hello,world,I,am,kandy";
    QStringList strlist = str.split(",");
    qDebug() << "strlist=" << strlist;
    //输出:strlist=("hello","world","I","am","kandy");
    
    //判断QStringList中是否包含某个成员
    bool bcontain = strlist.contains("kandy");
    qDebug() << "bcontain=" << bcontain;
    
    //移除QStringList中的成员
    strlist.removeOne("world");
    qDebug() << "after removeOne, strlist=" << strlist;

### QString 其他常用方法 ###

//QString定义
    QString s1 = "hello";
    QString s2("world");
    
    //字符串连接
    QString str = s1 + s2;
    
    //组包
    str = QString("a=%1, b=%2, c=%3").arg("hello").arg("world").arg("12.34");
    qDebug() << str;//"a=hello, b=world, c=12.34"
    
    str = "a=hello, b=world, c=12.34";
    //参数表示按逗号分隔,拆分出第0段到第1段
    QString tmp = str.section(",", 0, 1);
    qDebug() << "tmp=" << tmp;
    //tmp= "a=hello, b=world"
    
    //参数表示按逗号分隔,拆分出第0段到第0段
    tmp = str.section(",", 0, 0);
    qDebug() << "tmp=" << tmp;
    //tmp= "a=hello"
    
    
    //QString转char *
    
    //如果没有中文(即字符串为ASCII):
    QString ss1 = "hello test";
    QByteArray byte1 = ss1.toLatin1();
    char * szbuff1 = byte1.data();
    
    //如果有中文(即字符串为Unicode):
    QString ss2 = QString::fromStdWString(L"你好, 世界");
    QByteArray byte2 = ss2.toLocal8Bit();
    char * szbuff2 = byte2.data();
    
    //替换QString中字符串
    QString text("text-decoration: none");
    text.replace("none", "underline");
    qDebug() << "after replace, text=" << text;
    
    //字符移除操作
    QString sztmp = QString("hello,china").remove(2, 4); //从下标2的字符开始, 移除4个字符
    qDebug() << "sztmp=" << sztmp; //输出hechina
    
    //判断字符是否以某字符或字符串开始/结束(startsWith/endsWith)
    if (QString("@192.168.0.1#").startsWith("@"))
    { 
    	qDebug() << "startsWith(\"@\")";
    }
    if (QString("@192.168.0.1#").endsWith("#"))
    { 
    	qDebug() << "endsWith(\"#\")";
    }
    
    //判断QString是否空
    qDebug() << "QString().isEmpty()" << QString().isEmpty();			//true
    qDebug() << "QString("").isEmpty()" << QString("").isEmpty();		//true
    qDebug() << "QString(" ").isEmpty()" << QString(" ").isEmpty();		//false
    qDebug() << "QString(\"hi\").isEmpty()" << QString("hi").isEmpty();	//false
    
    qDebug() << "QString().isNull()" << QString().isNull();				//true
    qDebug() << "QString("").isNull()" << QString("").isNull();			//false
    qDebug() << "QString(" ").isNull()" << QString(" ").isNull();		//false
    qDebug() << "QString(\"hi\").isNull()" << QString("hi").isNull();	//false