c++11 随机数和随机颜色

1.c++11提供的random实现了随机数库，它通过随机数引擎类（random_number_engines)产生随机数序列，随机数分布类（random-number distribution)使用随机数引擎生成服从特定概率分布的随机数。

#include <iostream>
#include <random>
std::default_random_engine e;
std::uniform_real_distribution<double> random(0,1);
void SerialPortWidget::slotTest()
{
    qDebug()<<"r:"<<random(e)<<"i:"<<int(random(e)*255);

   //QColor color=QColorDialog::getColor(Qt::red,this,"选择颜色");
   btnTest->setStyleSheet("background-color:rgb("+QString::number(int(random(e)*255))+","
                           +QString::number(int(random(e)*255))+","
                           +QString::number(int(random(e)*255))+");");
}

private:
    std::default_random_engine randomEngine;
    std::uniform_real_distribution<double> randomNum;


OperationWidget::OperationWidget(QWidget *parent) : QWidget(parent),
    randomNum(0,1)
{
    this->setMaximumWidth(400);
    initUI();
}

QColor OperationWidget::getRandomColor()
{
    QColor c=QColor(int(randomNum(randomEngine)*255),int(randomNum(randomEngine)*255),
                    int(randomNum(randomEngine)*255));    
    return c;
}