c语言使用qrencode库实现二维码

1.源码实现

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <qrencode.h>
#include <cairo.h>

int main()
{
    cairo_surface_t *surface;
    cairo_t *cr;
    QRcode *qr = NULL;
    QRecLevel level = QR_ECLEVEL_L;
    QRencodeMode hint = QR_MODE_8;
    char *msg = "Hello World";
    int version = 1;
    int casesensitive = 1;
    unsigned char *qrData = NULL;
    int width = 0;
    int height = 0;
    int i, j;

    qr = QRcode_encodeString(msg, version, level, hint, casesensitive);
    if(qr == NULL)
    {
        printf("QRcode encodeString error!\n");
        return -1;
    }

    surface = cairo_image_surface_create(CAIRO_FORMAT_ARGB32, 300, 300);
        cr = cairo_create(surface);
        cairo_set_source_rgb(cr,0,0,0);

    qrData = qr->data;
    width = qr->width;
    height = qr->width;

    //printf("(%d, %d)\n", width, height);

    for(i=0; i<height; i++)
    {
        for(j=0; j<width; j++)
        {
            if(qrData[i*width+j] & 1)
            {
                //printf("(%d, %d)\n", i, j);
                cairo_rectangle(cr,45+i*10,45+j*10,10,10);
                cairo_fill(cr);
            }
        }
    }

    cairo_surface_write_to_png(surface, "a.png");
    cairo_destroy(cr);

    QRcode_free(qr);

    return 0;
}

2.编译源码

$ gcc -o example example.c -I$HOME/local/include -I/usr/include/cairo -L$HOME/local/lib  -lqrencode -lcairo

3.运行程序

$ ./example

4.结果查看