QString:: arg()方法

转载自：点击打开链接http://blog.163.com/qimo601@126/blog/static/1582209320134993927300/

QString 有多种方法,我慢慢总结中~~~~~~~~~~~~

1、QString::arg()//用字符串变量参数依次替代字符串中最小数值

Cpp代码

QString i = "iTest";           // current file's number  

QString total = "totalTest";       // number of files to process  

QString fileName = "fileNameTest";    // current file's name  

QString status = QString("Processing file %1 of %2: %3")  

                .arg(i).arg(total).arg(fileName);  

 style="background-color: #ffffff;">     qDebug() << status ;

结果就是："Processing file iTest of totalTest: fileNameTest"

First, arg(i) replaces %1. Then arg(total) replaces %2. Finally, arg(fileName) replaces %3.

fieldWidth specifies the minimum amount of space that argument a shall occupy. If a requires less space than fieldWidth, it is padded to fieldWidthwith character fillChar. A positive fieldWidth produces right-aligned text. A negative fieldWidth produces left-aligned text.

2、QString::arg ( int a, int fieldWidth = 0, int base = 10, const QChar & fillChar = QLatin1Char( ' ' ) ) const

a表示输入的值，fieldWidth表示字符宽度，base表示进制，fillChar 表示填充字符

若是字符宽度fieldWidth是正数，fillchar填在左边，若是负数，fillchar填在右边

16进制输出：

Cpp代码

QString str;  

str = QString("Decimal 63 is %1 in hexadecimal")  

        .arg(63, 0, 16);  

// str == "Decimal 63 is 3f in hexadecimal"  

QLocale::setDefault(QLocale(QLocale::English, QLocale::UnitedStates));  

str = QString("%1 %L2 %L3")  

        .arg(12345)  

        .arg(12345)  

        .arg(12345, 0, 16);  

// str == "12345 12,345 3039"  

//16进制显示，就忽略%L3的L  

//格式化输出

str = QString("%1").arg(521,5,10,QChar('a'))

//str =="aa521"