pdfmake.js是一个简单的生成pdf文件的插件。
pdfmake.js https://files.cnblogs.com/files/s313139232/pdfmake.min.js
参考：https://www.cnblogs.com/pheye/p/5661933.html
1.包含以下两个文件
<script src="build/pdfmake.min.js"></script>
<script src="build/vfs_fonts.js"></script> 2.在JS代码中声明一个Document-definition对象，这个是pdfmake自己的术语。简单点说，就是创建一个至少包含content属性的对象。然后就可以调用pdfMake的方法导出PDF，具体见如下代码：
<script type="text/javascript">
//创建Document-definition对象
var dd = {
content: [
'One paragraph',
'Another paragraph, this time a little bit longer to make sure, this line will be divided into at least two lines'
]
};
//导出PDF
pdfMake.createPdf(dd).download();
</script>在插入图片方面，jsPDF要求先将图片转换成Data URL才行，而pdfmake允许直接指定路径，看起来是很方便，但这是有条件的，必须是以node.js作为服务器，或者将图片放到vfs_fonts.js中，所以总的来说，用处不大，还是一样得将图片转换成Data URL形式才行。
为解决此问题，我写了一个ImageDataURL的函数对象，可同时传入多个图片地址。在图片都加载完成后，ImageDataURL.oncomplete将被触发，在回调中通过this.imgdata取出各个图片的Data URL，根据pdfmake的要求组织下，就可正确生成pdf了。
ImageDataURL的原理是通过H5的canvas标签，将图片绘制在canvas上，然后通过canvas的toDataURL得到图像的Data URL。使用时请注意浏览器兼容性问题。
以下为将sampleImage.jpg, sampleage.jpg, sampleImage.jpg依次写入PDF的例子，测试时sampleage.jpg不存在，PDF直接忽略。
<!DOCTYPE html>
<html lang="zh-CN">
<head>
<meta charset="utf-8">
<title>my second export PDF</title>
<script src="build/pdfmake.min.js"></script>
<script src="build/vfs_fonts.js"></script>
<script>
function down() {
var x = new ImageDataURL(["sampleImage.jpg", "samplage.jpg", "sampleImage.jpg"]);
x.oncomplete = function() {
var imgs = new Array();
console.log("complete");
for (key in this.imgdata) {
if (this.imgdata[key] == this.emptyobj){
continue;
}
imgs.push({image:this.imgdata[key]});
}
var dd = {
content: [
'Title',
imgs,
],
};
pdfMake.createPdf(dd).download();
}
}
</script>
</head>
<body>
<button onclick="down()">下载</button>
<script>
//urls必须是字符串或字符串数组
function ImageDataURL(urls) {
this.completenum = 0;
this.totalnum = 0;
this.imgdata = new Array();
this.emptyobj = new Object();
this.oncomplete = function(){};
this.getDataURL = function(url, index) {
var c = document.createElement("canvas");
var cxt = c.getContext("2d");
var img = new Image();
var dataurl;
var p;
p = this;
img.src = url;
img.onload = function() {
var i;
var maxwidth = 500;
var scale = 1.0;
if (img.width > maxwidth) {
scale = maxwidth / img.width;
c.width = maxwidth;
c.height = Math.floor(img.height * scale);
} else {
c.width= img.width;
c.height= img.height;
}
cxt.drawImage(img, 0, 0, c.width, c.height);
p.imgdata[index] = c.toDataURL('image/jpeg');
for (i = 0; i < p.totalnum; ++i) {
if (p.imgdata[i] == null)
break;
}
if (i == p.totalnum) {
p.oncomplete();
}
};
img.onerror = function() {
p.imgdata[index] = p.emptyobj;
for (i = 0; i < p.totalnum; ++i) {
if (p.imgdata[i] == null)
break;
}
if (i == p.totalnum) {
p.oncomplete();
}
};
}
if (urls instanceof Array) {
this.totalnum = urls.length;
this.imgdata = new Array(this.totalnum);
for (key in urls) {
this.getDataURL(urls[key], key);
}
} else {
this.imgdata = new Array(1);
this.totalnum = 1;
this.getDataURL(urls, 0);
}
}
</script>
</body>
</html>