QT QStringList 与 QString 常用方法

//method<1>
QString src1("hello kandy");
QByteArray ba1 = src1.toUtf8();

//method<2>
QString src2("hello kandy");
QByteArray ba2 = src2.toLatin1();

//method<1>
QByteArray ba1("hello world");
QString str1 = ba1;

//method<2>
QByteArray ba2("hello world");
QString str2;
str2.prepend(ba2);

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 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") */
}

//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