Qt+libqrencode+QZXing 二维码生成原理和识别

开发环境 Ubuntu18.04 + qt 5.9.3 +libqrencode + QZXing

先下载libqrencode，Git 地址：https://github.com/fukuchi/libqrencode

解压后，cmake 一下，然后make 编译。

编译成功，将静态库和头文件单独拷贝。

在项目pro中使用库。

#-------------------------------------------------

#

# Project created by QtCreator 2018-05-05T20:15:37

#

#-------------------------------------------------

QT
+= core gui

greaterThan(QT_MAJOR_VERSION, 4): QT += widgets

TARGET = Qrcode

TEMPLATE = app

# The following define makes your compiler emit warnings if you use

# any feature of Qt which has been marked as deprecated (the exact warnings

# depend on your compiler). Please consult the documentation of the

# deprecated API in order to know how to port your code away from it.

DEFINES += QT_DEPRECATED_WARNINGSa

# You can also make your code fail to compile if you use deprecated APIs.

# In order to do so, uncomment the following line.

# You can also select to disable deprecated APIs only up to a certain version of Qt.

#DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0x060000
# disables all the APIs deprecated before Qt 6.0.0

SOURCES += 

main.cpp 

mainwindow.cpp 

qrcode.cpp

HEADERS += 

mainwindow.h 

qrcode.h

FORMS += 

mainwindow.ui

unix:!macx: LIBS += -L$$PWD/../qrcode/ -lqrencode

INCLUDEPATH += $$PWD/../qrcode

DEPENDPATH += $$PWD/../qrcode

unix:!macx: PRE_TARGETDEPS += $$PWD/../qrcode/libqrencode.a

unix:!macx: LIBS += -L$$PWD/../QZXing/ -lQZXing

INCLUDEPATH += $$PWD/../QZXing

DEPENDPATH += $$PWD/../QZXing

QRcodeEncode 源码：

#ifndef QRCODE_H
#define QRCODE_H
#include "qrencode.h"
#include <QColor>
#include <QPainter>
class QRcodeEncode
{
public:
QRcodeEncode();
void setString(QString str);
int getQRWidth() const;
bool saveImage(QString name ,int size);
~QRcodeEncode();
void draw(QPainter &painter, int width, int height);
private:
QRcode* qr;
QString string;
};
#endif // QRCODE_H

#include "qrcode.h"
QRcodeEncode::QRcodeEncode()
{
qr = new QRcode();
}
int QRcodeEncode::getQRWidth() const
{
if(qr != NULL)
{
return qr->width;
}
else
{
return 0;
}
}
QRcodeEncode::~QRcodeEncode()
{
if(qr != NULL)
{
QRcode_free(qr);
}
}
void QRcodeEncode::setString(QString str)
{
string = str;
if(qr != NULL)
{
QRcode_free(qr);
}
qr = QRcode_encodeString(string.toStdString().c_str(),1,QR_ECLEVEL_L,QR_MODE_8,1);
}
bool QRcodeEncode::saveImage(QString fileName, int size)
{
if(size != 0 && !fileName.isEmpty())
{
QImage image(size, size, QImage::Format_Mono);
QPainter painter(&image);
QColor background(Qt::white);
painter.setBrush(background);
painter.setPen(Qt::NoPen);
painter.drawRect(0, 0, size, size);
if(qr != NULL)
{
draw(painter, size, size);
}
return image.save(fileName);
}
else
{
return false;
}
}
void QRcodeEncode::draw(QPainter &painter, int width, int height)
{
QColor foreground(Qt::black);
painter.setBrush(foreground);
const int qr_width = qr->width > 0 ? qr->width : 1;
double scale_x = width / qr_width;
double scale_y = height / qr_width;
for( int y = 0; y < qr_width; y ++)
{
for(int x = 0; x < qr_width; x++)
{
unsigned char b = qr->data[y * qr_width + x];
if(b & 0x01)
{
QRectF r(x * scale_x, y * scale_y, scale_x, scale_y);
painter.drawRects(&r, 1);
}
}
}
}

下载解码库 QZXing，https://github.com/ftylitak/qzxing/

解压后用Qt编译source中的源码。

编译完成后将库和头文件单独拷贝：

libQZXing.so    libQZXing.so.2.3    QZXing_global.h

libQZXing.so.2  libQZXing.so.2.3.0  qzxing.h

在项目中使用库。

窗体源码。

#ifndef MAINWINDOW_H
#define MAINWINDOW_H
#include <QMainWindow>
#include "qrcode.h"
#include <QPainter>
#include "qzxing.h"
#include <QDebug>
namespace Ui {
class MainWindow;
}
class MainWindow : public QMainWindow
{
Q_OBJECT
public:
explicit MainWindow(QWidget *parent = 0);
~MainWindow();
protected:
void paintEvent(QPaintEvent*);
QSize sizeHint() const;
QSize minimumSizeHint() const;
private:
QString string;
QRcodeEncode *m_qrcode;
Ui::MainWindow *ui;
};
#endif // MAINWINDOW_H

#include "mainwindow.h"
#include "ui_mainwindow.h"
MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);
m_qrcode
=
new QRcodeEncode();
m_qrcode->setString("Hello QR Code");
QImage img;//解码很简单
img.load("/home/rui/Code/build-Qrcode-Desktop_Qt_5_9_3_GCC_64bit-Debug/Qrcode.png");
QZXing qzxing;
qDebug()<<qzxing.decodeImage(img);
}
MainWindow::~MainWindow()
{
delete ui;
}
QSize MainWindow::sizeHint() const
{
QSize s;
if(m_qrcode != NULL)
{
int qr_width = m_qrcode->getQRWidth() > 0 ? m_qrcode->getQRWidth() : 1;
s = QSize(qr_width*4,qr_width*4);
}
else
{
s = QSize(50,50);
}
return s;
}
QSize MainWindow::minimumSizeHint() const
{
QSize s;
if(m_qrcode != NULL)
{
int qr_width = m_qrcode->getQRWidth() > 0 ? m_qrcode->getQRWidth() : 1;
s = QSize(qr_width,qr_width);
}
else
{
s = QSize(50, 50);
}
return s;
}
void MainWindow::paintEvent(QPaintEvent *)
{
QPainter painter(this);
QColor background(Qt::white);
painter.setBrush(background);
painter.setPen(Qt::NoPen);
painter.drawRect(0, 0, width(), height());
if(m_qrcode != NULL)
{
m_qrcode->draw(painter, width(), height());
}
}

生成和解码：

最后

以上就是激动眼睛为你收集整理的Qt+libqrencode+QZXing 二维码生成原理和识别的全部内容，希望文章能够帮你解决Qt+libqrencode+QZXing 二维码生成原理和识别所遇到的程序开发问题。

如果觉得靠谱客网站的内容还不错，欢迎将靠谱客网站推荐给程序员好友。