我对 nodeJs
还比较新手,正在尝试在服务器端使用 jsPdf
生成 PDF 文件。
我已经使用 npm install jspdf --save
命令安装了 jspdf。
由于 nodeJs 不支持 jspdf 中所使用的 atob
,因此我执行了以下命令:
npm install atob --save
并添加了以下内容:
var atob = require('atob');
var PNG = require('png-js');
在使用jspdf
添加png文件时,需要使用png-js
。以下代码尝试将PNG文件添加到PDF中:
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");
}
});
以下错误被触发。
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?它在JPEG图像上运行良好。
日志中的图像数据
data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAA...QmCC