echarts无法打印解决
修改print.js的getHtml，增加对canvas的处理，将echarts转为图片：
getHtml: function () {
var inputs = document.querySelectorAll('input');
var textareas = document.querySelectorAll('textarea');
var selects = document.querySelectorAll('select');
var canvass = document.querySelectorAll('canvas');
for (var k = 0; k < inputs.length; k++) {
if (inputs[k].type == "checkbox" || inputs[k].type == "radio") {
if (inputs[k].checked == true) {
inputs[k].setAttribute('checked', "checked")
} else {
inputs[k].removeAttribute('checked')
}
} else if (inputs[k].type == "text") {
inputs[k].setAttribute('value', inputs[k].value)
} else {
inputs[k].setAttribute('value', inputs[k].value)
}
}
for (var k2 = 0; k2 < textareas.length; k2++) {
if (textareas[k2].type == 'textarea') {
textareas[k2].innerHTML = textareas[k2].value
}
}
for (var k3 = 0; k3 < selects.length; k3++) {
if (selects[k3].type == 'select-one') {
var child = selects[k3].children;
for (var i in child) {
if (child[i].tagName == 'OPTION') {
if (child[i].selected == true) {
child[i].setAttribute('selected', "selected")
} else {
child[i].removeAttribute('selected')
}
}
}
}
}
//canvass echars图表转为图片
for (var k4 = 0; k4 < canvass.length; k4++) {
var imageURL = canvass[k4].toDataURL("image/png");
var img = document.createElement("img");
img.src = imageURL;
img.setAttribute('style', 'max-width: 100%;');
img.className = 'isNeedRemove'
canvass[k4].parentNode.insertBefore(img,canvass[k4].nextElementSibling);
}
},
el-table打印不全
image.png
方法一：修改print.js的getHtml方法，增加对表格的宽度处理
getHtml: function () {
var inputs = document.querySelectorAll("input");
var textareas = document.querySelectorAll("textarea");
var selects = document.querySelectorAll("select");
let cells = document.querySelectorAll(".cell");
for (var k = 0; k < inputs.length; k++) {
if (inputs[k].type == "checkbox" || inputs[k].type == "radio") {
if (inputs[k].checked == true) {
inputs[k].setAttribute("checked", "checked");
} else {
inputs[k].removeAttribute("checked");
}
} else if (inputs[k].type == "text") {
inputs[k].setAttribute("value", inputs[k].value);
} else {
inputs[k].setAttribute("value", inputs[k].value);
}
}
for (var k2 = 0; k2 < textareas.length; k2++) {
if (textareas[k2].type == "textarea") {
textareas[k2].innerHTML = textareas[k2].value;
}
}
for (var k3 = 0; k3 < selects.length; k3++) {
if (selects[k3].type == "select-one") {
var child = selects[k3].children;
for (var i in child) {
if (child[i].tagName == "OPTION") {
if (child[i].selected == true) {
child[i].setAttribute("selected", "selected");
} else {
child[i].removeAttribute("selected");
}
}
}
}
}
const tableNode = document.querySelectorAll(
".el-table__header,.el-table__body"
);
console.log(tableNode);
//el-table 打印预览的时候，宽度占满
for (let k6 = 0; k6 < tableNode.length; k6++) {
const tableItem = tableNode[k6];
tableItem.style.width = "100%";
}
return this.dom.outerHTML;
},
image.png
方法二：将el-table改为table（虽然麻烦但是好用）
利用table分页可以让行不被截断且每一页都有表头
参考如下链接：
https://www.jianshu.com/p/4d90efbae014
方法三：结合html2Canvas将打印的页面转为图片
这条同样可以解决echarts不能打印问题，算是万能之法了吧，相对前面几种方式赶紧这个方法最简单，打印效果也比较理想。
1、首先需要安装html2canvas 和print-js 插件并引入，配置请参考文档：https://github.com/niklasvh/html2canvas
2、写一个打印公共方法：
//html转图片打印（解决element table打印不全的问题）
import html2canvas from "html2canvas";
import printJS from "print-js";
/**
* html转图片
* @param printContent
* @param callback
*/
export const html2Canvas = (printContent, callback) => {
// 获取dom 宽度 高度
const width = printContent.clientWidth;
const height = printContent.clientHeight;
// 创建一个canvas节点
const canvas = document.createElement("canvas");
const scale = 4; // 定义任意放大倍数，支持小数；越大，图片清晰度越高，生成图片越慢。
canvas.width = width * scale; // 定义canvas 宽度 * 缩放
canvas.height = height * scale; // 定义canvas高度 *缩放
canvas.style.width = width * scale + "px";
canvas.style.height = height * scale + "px";
canvas.getContext("2d").scale(scale, scale); // 获取context,设置scale
const scrollTop =
document.documentElement.scrollTop || document.body.scrollTop; // 获取滚动轴滚动的长度
const scrollLeft =
document.documentElement.scrollLeft || document.body.scrollLeft; // 获取水平滚动轴的长度
html2canvas(printContent, {
canvas,
backgroundColor: null,
useCORS: true,
windowHeight: document.body.scrollHeight,
scrollX: -scrollLeft, // 解决水平偏移问题，防止打印的内容不全
scrollY: -scrollTop
//background: "#ffffff", // 一定要添加背景颜色，否则出来的图片，背景全部都是透明的
})
.then(canvas => {
const url = canvas.toDataURL("image/png");
//console.log("canvas url :" + url);
callback({ url: url });
})
.catch(err => {
console.error(err);
});
};
/**
* 用printJs打印图片
* @param url
* @param callback
*/
export const printImg = (url, callback) => {
printJS({
printable: url,
type: "image",
documentTitle: "", // 标题
style: "@page{size:auto;margin: 1cm ;}", // 去除页眉页脚
onStart: () => {
console.log("打印开始");
},
onEnd: () => {
console.log("打印完成");
}
});
};
/**
* html转图片打印
* @param dom
* @param callback
*/
export const html2CanvasPrint = (dom, callback) => {
//1、html转图片
html2Canvas(dom, canvasRes => {
//2、打印图片
printImg(canvasRes.url, callback);
});
};
3、调用方法：
html2Canvas(this.$refs.printDom, res => {
this.printDomUrl = res.url;
printImg(res.url, printRes => {});
});
