Qt 正则表达式：生成指定范围数值的正则表达式接口（整数和小数都可以）

int getExpNext(int num,int max)
{
    QString chars = QString::number(num);
    for (int i=chars.length()-1;  i>=0 ; i--)
    {
        if (chars[i]=='0')
        {
            chars[i] = '9';
        }
        else
        {
            chars[i] = '9';
            break;
        }
    }
    int value = chars.toInt();
    if(value < max)
        return chars.toInt();
    chars = QString::number(num);
    QString charsMax = QString::number(max);
    if(charsMax.length() == chars.length())
    {
        for (int i=0; i < chars.length(); i++)
        {
            if (chars[i] < charsMax[i])
            {
                if(i == chars.length()-1)
                {
                    return max;
                }
                else
                {
                    chars[i] = '0' + charsMax.at(i).toLatin1() - '0'-1;
                    for(int j = i+1; j < chars.length(); j++)
                    {
                        chars[j] = '9';
                    }
                }
                return chars.toInt();
            }
        }
    }
    return max;
}
//指定范围和小数位数，生成一个正则表达式，
    //min 最小值，max最大值，decimalCount 小数位数，即只能输入min~max范围的数值，最多decimalCount位小数位，如果decimalCount=0，就是整数
    QString getExpStr(int min,int max,int decimalCount)
    {
        if(min > max)
            return "";
        if(min == max)
            return QString::number(min);

        QList<int> minList;
        QList<int> maxList;
        max--;
        int value = min;
        int temp = value;
        while (value < max)
        {
            temp = value;
            value = getExpNext(value,max);
            minList << temp;
            maxList << value;
            value++;
        }
        QString expStr;
        if(max % 10 == 0)
            expStr+= QString("(%1)").arg(max);
        for(int i =0; i < minList.count(); i++)
        {
            QString minStr = QString::number(minList[i]);
            QString maxStr = QString::number(maxList[i]);
            QString str = QString("(");
            for(int j = 0 ; j < minStr.length(); j++)
            {
                if(minStr[j] == maxStr[j])
                {
                    str +=minStr[j];
                }
                else
                    str += QString("[%1-%2]").arg(minStr[j]).arg(maxStr[j]);
            }
            str += ")";
            if(!expStr.isEmpty())
                expStr += "|";
            expStr += str;
        }
        if(decimalCount > 0)
            expStr = QString("^(%1|(%4))|((%2)%3)$").arg(expStr).arg(expStr).arg(QString("\\.[0-9]{%1}").arg(decimalCount)).arg(max+1);
        else
            expStr = QString("^(%1|(%2))$").arg(expStr).arg(max+1);
        return expStr ;
    }

例子：

    int min = ui->lineEdit->text().toInt();
    int max = ui->lineEdit_2->text().toInt();
    QRegExp regx(getExpStr(min,max,3));
    ui->lineEdit_3->setValidator( new QRegExpValidator(regx,this));