将vue页面抓屏导出为图片或者PDF文件

导出为图片
1.将页面html转换成图片 npm install html2canvas --save
2.在需要导出的页面引入 import html2canvas from 'html2canvas';
3.在 methods 中添加方法

dataURLToBlob(dataurl) {//ie 图片转格式
    var arr = dataurl.split(','), mime = arr[0].match(/:(.*?);/)[1],
    bstr = atob(arr[1]), n = bstr.length, u8arr = new Uint8Array(n);
    while (n--) {
        u8arr[n] = bstr.charCodeAt(n);
    }
    return new Blob([u8arr], {type: mime})
},
 
downloadResult(name) {
    let canvasID = document.body
    let a = document.createElement('a');
    html2canvas(canvasID).then(canvas => {
        let dom = document.body.appendChild(canvas);
        dom.style.display = "none";
        a.style.display = "none";
        document.body.removeChild(dom);
        let blob = this.dataURLToBlob(dom.toDataURL("image/png"));
        a.setAttribute("href", URL.createObjectURL(blob));
        a.setAttribute("download", name + ".png")
        document.body.appendChild(a);
        a.click();
        URL.revokeObjectURL(blob);
        document.body.removeChild(a);
    });
},
 
printOut(name) {
    // 个人观察只是截取可见范围以及以下的区域，所以先将滚动条置顶
    $(window).scrollTop(0); // jQuery 的方法
    document.body.scrollTop = 0; // IE的
    document.documentElement.scrollTop = 0; // 其他
    this.downloadResult(name)
},
 
  
 
导出为PDF
1.将页面html转换成图片  npm install html2canvas --save
2.将图片生成pdf  npm install jspdf --save
3.在需要导出的页面引入  import html2canvas from 'html2canvas';  
                      import JsPDF from 'jspdf'
4.在 methods 中添加方法
printOut(name) {
    let shareContent = document.body,//需要截图的包裹的（原生的）DOM 对象
    width = shareContent.clientWidth, //获取dom 宽度
    height = shareContent.clientHeight, //获取dom 高度
    canvas = document.createElement("canvas"), //创建一个canvas节点
    scale = 2; //定义任意放大倍数 支持小数
    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 = shareContent.clientWidth * scale + "px";
    canvas.style.height = shareContent.clientHeight * scale + "px";
    canvas.getContext("2d").scale(scale, scale); //获取context,设置scale
    let opts = {
        scale: scale, // 添加的scale 参数
        canvas: canvas, //自定义 canvas
        logging: false, //日志开关，便于查看html2canvas的内部执行流程
        width: width, //dom 原始宽度
        height: height,
        useCORS: true, // 【重要】开启跨域配置
    };
 
    html2Canvas(shareContent, opts).then(() => {
        var contentWidth = canvas.width;
        var contentHeight = canvas.height;
        //一页pdf显示html页面生成的canvas高度;
        var pageHeight = (contentWidth / 592.28) * 841.89;
        //未生成pdf的html页面高度
        var leftHeight = contentHeight;
        //页面偏移
        var position = 0;
        //a4纸的尺寸[595.28,841.89]，html页面生成的canvas在pdf中图片的宽高
        var imgWidth = 595.28;
        var imgHeight = (592.28 / contentWidth) * contentHeight;
        var pageData = canvas.toDataURL("image/jpeg", 1.0);
        var PDF = new JsPDF("", "pt", "a4");
        if (leftHeight < pageHeight) {
            PDF.addImage(pageData, "JPEG", 0, 0, imgWidth, imgHeight);
        } else {
            while (leftHeight > 0) {
                PDF.addImage(pageData, "JPEG", 0, position, imgWidth, imgHeight);
                leftHeight -= pageHeight;
                position -= 841.89;
                if (leftHeight > 0) {
                    PDF.addPage();
                }
            }
        }
        PDF.save(name + ".pdf"); // 这里是导出的文件名
    });
}