QT子线程画图

1.业务类

MyWork.h

#ifndef MYWORK_H
#define MYWORK_H

#include <QObject>
#include <QImage>

class MyWork : public QObject
{
    Q_OBJECT
public:
    explicit MyWork(QObject *parent = 0);
    // 添加画图函数
    void drawImage();

signals:
    void imageDone(QImage image);

public slots:
};

#endif // MYWORK_H

MyWork.cpp

#include "mywork.h"
#include <QPainter>

MyWork::MyWork(QObject *parent) : QObject(parent)
{

}

void MyWork::drawImage()
{
    QImage image(600, 600, QImage::Format_RGB32);
    QPainter p(&image);

    // 设置画笔
    p.setPen(QPen(Qt::blue, 10));
    // 设置画刷
    p.setBrush(Qt::red);

    // 画多边形
    QPoint points[] =
    {
        QPoint(qrand()%500, qrand()%500),
        QPoint(qrand()%500, qrand()%500),
        QPoint(qrand()%500, qrand()%500),
        QPoint(qrand()%500, qrand()%500),
        QPoint(qrand()%500, qrand()%500),