將vue頁面導出為圖片或者PDF文件

導出為圖片
1.將頁面html轉換成圖片   npm install html2canvas --save
2.在需要導出的頁面引入  import html2canvas from 'html2canvas';
3.在 methods 中添加方法  
dataURLToBlob(dataurl) {//ie 圖片轉格式
    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) {
    // 個人觀察只是截取可見范圍以及以下的區域，所以先將滾動條置頂
    $(window).scrollTop(0); // jQuery 的方法
    document.body.scrollTop = 0; // IE的
    document.documentElement.scrollTop = 0; // 其他
    this.downloadResult(name)
},

 

導出為PDF
1.將頁面html轉換成圖片  npm install html2canvas --save
2.將圖片生成pdf  npm install jspdf --save
3.在需要導出的頁面引入  import html2canvas from 'html2canvas';   import JsPDF from 'jspdf'
4.在 methods 中添加方法
printOut(name) {
    let shareContent = document.body,//需要截圖的包裹的（原生的）DOM 對象
    width = shareContent.clientWidth, //獲取dom 寬度
    height = shareContent.clientHeight, //獲取dom 高度
    canvas = document.createElement("canvas"), //創建一個canvas節點
    scale = 2; //定義任意放大倍數 支持小數
    canvas.width = width * scale; //定義canvas 寬度 * 縮放
    canvas.height = height * scale; //定義canvas高度 *縮放
    canvas.style.width = shareContent.clientWidth * scale + "px";
    canvas.style.height = shareContent.clientHeight * scale + "px";
    canvas.getContext("2d").scale(scale, scale); //獲取context,設置scale
    let opts = {
        scale: scale, // 添加的scale 參數
        canvas: canvas, //自定義 canvas
        logging: false, //日志開關，便於查看html2canvas的內部執行流程
        width: width, //dom 原始寬度
        height: height,
        useCORS: true, // 【重要】開啟跨域配置
    };

    html2Canvas(shareContent, opts).then(() => {
        var contentWidth = canvas.width;
        var contentHeight = canvas.height;
        //一頁pdf顯示html頁面生成的canvas高度;
        var pageHeight = (contentWidth / 592.28) * 841.89;
        //未生成pdf的html頁面高度
        var leftHeight = contentHeight;
        //頁面偏移
        var position = 0;
        //a4紙的尺寸[595.28,841.89]，html頁面生成的canvas在pdf中圖片的寬高
        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"); // 這里是導出的文件名
    });
},