使用nodejs和jspdf在pdf中添加png图像

Question

我很陌生nodeJs，我正在尝试在服务器上创建 pdf jsPdf。

我已经使用安装了 jspdfnpm install jspdf --save

由于nodeJs不支持atobjspdf中使用的功能，因此我添加了

npm install atob --save 并添加了

var atob = require('atob');
var PNG = require('png-js');

在哪里png-js添加 png 文件是必需的jspdf。当我尝试使用以下代码将 PNG 文件添加到 pdf 时

let imgData=request.payload.canvasobj;
let pdfContent = new jsPDF();
pdfContent.addImage(imgData, 'PNG',  40, 20, 0, 0);
let data = pdfContent.output('arraybuffer');
let buffer = Buffer.from(data);
let arraybuffer = Uint8Array.from(buffer);
fs.appendFile('./canvas.pdf', new Buffer(arraybuffer), function (err) {
    if (err) {
        console.log(err);
    } else {
        console.log("PDF created");
    }
});

触发以下错误

Debug: internal, implementation, error
    TypeError: Uncaught error: Cannot read property 'buffer' of undefined
    at Object.jsPDFAPI.processPNG (C:\LearningPro\NodeJsProjects\pdfexport-nodejs\node_modules\jspdf\dist\jspdf.debug.js:8796:80)
    at Object.jsPDFAPI.addImage (C:\LearningPro\NodeJsProjects\pdfexport-nodejs\node_modules\jspdf\dist\jspdf.debug.js:4696:50)
    at canvas (C:\LearningPro\NodeJsProjects\pdfexport-nodejs\requestHandler.js:105:16)
    at Object.internals.handler (C:\LearningPro\NodeJsProjects\pdfexport-nodejs\node_modules\hapi\lib\handler.js:99:36)
    at request._protect.run (C:\LearningPro\NodeJsProjects\pdfexport-nodejs\node_modules\hapi\lib\handler.js:30:23)
    at internals.Protect.run (C:\LearningPro\NodeJsProjects\pdfexport-nodejs\node_modules\hapi\lib\protect.js:59:12)
    at exports.execute (C:\LearningPro\NodeJsProjects\pdfexport-nodejs\node_modules\hapi\lib\handler.js:24:22)
    at each (C:\LearningPro\NodeJsProjects\pdfexport-nodejs\node_modules\hapi\lib\request.js:382:16)
    at iterate (C:\LearningPro\NodeJsProjects\pdfexport-nodejs\node_modules\hapi\node_modules\items\lib\index.js:36:13)
    at done (C:\LearningPro\NodeJsProjects\pdfexport-nodejs\node_modules\hapi\node_modules\items\lib\index.js:28:25)
Debug: internal, implementation, error
    TypeError: fn is not a function
    at C:\LearningPro\NodeJsProjects\pdfexport-nodejs\node_modules\png-js\png-node.js:246:16
    at Inflate.onEnd (zlib.js:227:5)
    at emitNone (events.js:91:20)
    at Inflate.emit (events.js:185:7)
    at endReadableNT (_stream_readable.js:974:12)
    at _combinedTickCallback (internal/process/next_tick.js:74:11)
    at process._tickDomainCallback (internal/process/next_tick.js:122:9)

我错过了什么？它与 JPEG 图像配合良好。

日志中的图像数据

data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAA...QmCC

Answer 1

var path_url = '/usr/logo.png', format = 'PNG';    
//format 'JPEG', 'PNG', 'WEBP'    
var imgData = fs.readFileSync(path_url).toString('base64');    
var doc = new jsPDF();    
doc.addImage(imgData, format, 0, 0, 5, 1)