QPainter. QpaintDevice 绘图设备

QPaintDevice 绘图设备

1 QPixmap QImage Qbitmap(黑白色) QPicture QWidget

2 QPixmap 对不同平台做了显示优化  fill(填充颜色) QPainter paintere(&pic) 画家往设备上画 画完保存 save("路径")

3 QImage 可以对像素进行访问，和 QPixmap 差不多 对像素进行修改 img.setPixel();

4 Qpicture 记录和重现绘图指令。save 的时候可以上任意后缀名称 重现利用画家 painter.drawPicture();

widget.h

#ifndef WIDGET_H

#define WIDGET_H

#include <QWidget>

QT_BEGIN_NAMESPACE

namespace Ui { class Widget; }

QT_END_NAMESPACE

class Widget : public QWidget

{

    Q_OBJECT

public:

    Widget(QWidget *parent = nullptr);

    ~Widget();

protected:

    void paintEvent(QPaintEvent * even);

private:

    Ui::Widget *ui;

};

#endif // WIDGET_H

widght.cpp

#include "widget.h"

#include "ui_widget.h"

#include<QPixmap>

#include<QPainter>

#include<QImage>

#include<QPicture>

Widget::Widget(QWidget *parent)

    : QWidget(parent)

    , ui(new Ui::Widget)

{

    ui->setupUi(this);

    //绘画设备专门为为平台做显示优化的

    QPixmap pixmap(300,300);

    pixmap.fill(Qt::white);//填充颜色

    QPainter painter(&pixmap);

    painter.setPen(QPen(Qt::green)); //设置绿色

    //在设备上画圆

    painter.drawEllipse(QPoint(100,100),100,100);//在点100，100 的位置画圆

    pixmap.save("/Users/libin/qtProject/painterDraw/pix.png");

     //////图片//////Qimag

     QImage imag(300,300,QImage::Format_ARGB32);

     QPainter painter2(&imag);

     painter2.setPen(QPen(Qt::red));

     painter2.drawEllipse(QPoint(150,150),100,100);

     imag.save("/Users/libin/qtProject/painterDraw/imag.png");

     ////QPictrue///////////绘图设备可以记录和重现绘图指令

     QPicture picture;

     QPainter painter4;

     painter4.setPen(QPen(Qt::red));

     painter4.begin(&picture); //开始往设备上画

     painter4.drawEllipse(QPoint(20,20),200,200);

     painter4.end();//结束

     picture.save("/Users/libin/qtProject/paintDevice/pic.zt");

}

void Widget::paintEvent(QPaintEvent *even){

    QImage img;

    img.load(":/mm.png");

    QPainter painter3(this);

    for(int i =0;i<200;++i){

        for(int j = 0;j<200;++j){

            QRgb rbg = qRgb(255,i,j);

            img.setPixel(i,j,rbg);

        }

    }

    painter3.drawImage(0,0,img);

    //读取画笔指令

    QPainter q5(this);

    QPicture picture3;

    picture3.load("/Users/libin/qtProject/paintDevice/pic.zt");

    q5.drawPicture(0,0,picture3);

}

Widget::~Widget()

{

    delete ui;

}

QPainter. QpaintDevice 绘图设备的相关教程结束。