PDF库 libharu 简单操作

libharu官网：http://libharu.org/

直接下载下来编译就可以使用了（*：我下载的版本是：libharu-libharu-v2.4.3-0-g8dbcfe4.tar）

 

一、编译

官方编译指导：https://github.com/libharu/libharu/wiki/Installation

1. 解压
tar -zxvf libharu-libharu-v2.4.3-0-g8dbcfe4.tar

2.在解压出来文件夹中创建一个build文件夹
mkdir build

3.进入build文件夹
cd build

4.使用cmake编译
cmake ..

5.make编译
make

6.编译出来的 libhpdf.so 就是我们需要的库文件

*：在引入头文件时，需要把 build/include/hpdf_config.h 文件一起拿出来，不然会报错缺少文件

二、基本使用

// 简单添加一张图片到PDF文件中，图片按比例显示，PDF文件页面边距50px
int main2()
{
    HPDF_Doc pdf = HPDF_New(NULL, NULL);

    // 创建PDF文件和页面
    HPDF_Page page = HPDF_AddPage (pdf);
    HPDF_Page_SetSize (page, HPDF_PAGE_SIZE_A4, HPDF_PAGE_PORTRAIT);
    HPDF_REAL page_width = HPDF_Page_GetWidth(page);
    HPDF_REAL page_height = HPDF_Page_GetHeight(page);
    cout << "page width:" << page_width << " height:" << page_height << endl;

    // 加载图片到页面上,PDF的坐标是从左下角计算的
    HPDF_Image image = HPDF_LoadJpegImageFromFile (pdf, "./files/1.jpg");
    HPDF_REAL width = HPDF_Image_GetWidth(image);
    HPDF_REAL height = HPDF_Image_GetHeight(image);
    HPDF_REAL image_scale = width / (page_width-100);
    HPDF_Page_DrawImage(page, image, 50, page_height - height / image_scale - 50, width / image_scale, height / image_scale);
    cout << "image width:" << width << " height:" << height << endl;

    HPDF_SaveToFile (pdf, "1.pdf");
    HPDF_Free (pdf);

    cout << "save success" << endl;

    return 0;
}

// 添加多张图片到PDF文件中，一张图片一个页面
int main()
{
    HPDF_Doc pdf = HPDF_New(NULL, NULL);

    vector<string> files = {"./files/1.jpg", "./files/2.jpg", "./files/3.jpg"};
    for(int i=0; i<files.size(); i++)
    {
        HPDF_Page page = HPDF_AddPage(pdf);
        HPDF_Page_SetSize (page, HPDF_PAGE_SIZE_A4, HPDF_PAGE_PORTRAIT);

        HPDF_Image image = HPDF_LoadJpegImageFromFile(pdf, files.at(i).c_str());
        HPDF_Page_DrawImage(page, image, 50, 50, HPDF_Image_GetWidth(image), HPDF_Image_GetHeight(image));
    }

    HPDF_SaveToFile(pdf, "2.pdf");
    HPDF_Free(pdf);
}

// 图片是什么尺寸，PDF的page页面就是什么尺寸
int main()
{
    HPDF_Doc pdf = HPDF_New(NULL, NULL);
    HPDF_SetCompressionMode(pdf, HPDF_COMP_ALL);    // 压缩

    vector<string> files = { "./files/1.jpg", "./files/2.jpg", "./files/3.jpg" };
    for (int i = 0; i < files.size(); i++)
    {
        HPDF_Image image = HPDF_LoadJpegImageFromFile(pdf, files.at(i).c_str());
        HPDF_REAL image_width = HPDF_Image_GetWidth(image);
        HPDF_REAL image_height = HPDF_Image_GetHeight(image);

        HPDF_Page page = HPDF_AddPage(pdf);
        HPDF_Page_SetWidth(page, image_width);
        HPDF_Page_SetHeight(page, image_height);

        // 设置缩放
        HPDF_Destination dst = HPDF_Page_CreateDestination(page);
        HPDF_Destination_SetXYZ(dst, 0, HPDF_Page_GetHeight(page), 1);
        HPDF_SetOpenAction(pdf, dst);

        HPDF_Page_DrawImage(page, image, 0, 0, image_width, image_height);
    }

    HPDF_SaveToFile(pdf, "1.pdf");
    HPDF_Free(pdf);
}