js 打印

    // 打印图片
    function printThisWindow(url) {
        let iframe = document.createElement('IFRAME')
        let doc = null
        iframe.setAttribute('class', 'print-iframe')
        iframe.setAttribute('style', 'position:absolute;width:0px;height:0px;left:-500px;top:-500px;')
        document.body.appendChild(iframe)
        doc = iframe.contentWindow.document
        doc.___imageLoad___ = function () {
            iframe.contentWindow.print()
            if (navigator.userAgent.indexOf('MSIE') > 0) {
                document.body.removeChild(iframe)
            }
        }
        doc.write('<div style="height: 100%;width: 100%;">' + `<img src="${url}" style="max-height:100%;max-width: 100%;" onload="___imageLoad___()"/>` + '</div>')
        doc.close()
        iframe.contentWindow.focus()
    }

    // 打印当前页面
    function doPrint() {
        bdhtml = window.document.body.innerHTML;
        sprnstr = "<!--startprint-->"; //开始打印标识字符串有17个字符
        eprnstr = "<!--endprint-->"; //结束打印标识字符串
        prnhtml = bdhtml.substr(bdhtml.indexOf(sprnstr) + 17);
        prnhtml = prnhtml.substring(0, prnhtml.indexOf(eprnstr));
        window.document.body.innerHTML = prnhtml;
        // print.portrait   =  false    ;//横向打印
        window.print(); //调用浏览器的打印功能打印指定区域
        window.document.body.innerHTML = bdhtml; // 最后还原页面
    }