Qt QString常用方法

Posted 2023-03-21

参考技术A QString

Qt中的QString和QStringList常用方法

QString

QString s1 = "abc";
QString s2("hello");
//字符串连接
QString s = s1 + s2;

//组包
s = QString("a = %1, b = %2, c = %3").arg(250).arg("hello").arg(22.22);
qDebug()<<s;
//输出结果:a = 250, b = hello, c = 22.22

s = "a=250,b=hello,c=22.22";
//参数表示按逗号分隔, 拆分出第0段到第1段, 保存到tmp
QString tmp = s.section(",", 0, 1);
qDebug()<<"tmp = "<<tmp;
//输出结果:tmp="a=250"

tmp = tmp.section("=", 1, 1);
qDebug()<<"tmp="<<tmp;
//输出结果:tmp="250";

//QString转int
int a = tmp.toInt();
qDebug()<<"a="<<a;
//输出结果:a=250;

//int转QString组包方式转
tmp = QString("%1").arg(123);
qDebug()<<"tmp="<<tmp;
//输出结果:tmp="123"

//int转QString函数方式转
tmp = QString::number(234);

//char *转QString
const char * buf = "hello, world";
QString ss = buf;
qDebug()<<"ss = "<< ss;

//字符数组转QString
char buf2[100] = "hello world";
ss = buf2;
qDebug()<<"ss = "<<ss;

//QString转char *
ss = "hello abc";
char * buf3 = ss.toLocal8Bit().data();//转换为本地编码
char * buf4 = ss.toUtf8().data();//转换为utf-8编码

QStringList

//定义
QStringList list;
//添加字符串
list << "hello";
list << "world";
list.append("abc");
//打印
qDebug()<< "list ="<< list;
//遍历
for(int i = 0; i< list.size();++i)
{
    QString tmp = list.at(i);
    qDebug()<<"tmp ="<< tmp; 
}

//使用QStringList拆分QString
QString str = "hello,world,abc,qt";
QStringList list2 = str.split(",");
qDebug()<<"list2="<<list2;
//输出:list2=("hello","world","abc","qt");

//判断QStringList中是否包含某个成员
bool b = list2.contains("123");

//移除QStringList中的成员
list2.removeOne("abc");