下面的代码复制了查询选择器目标的所有相关节点，复制了它们在屏幕上看到的样式，因为许多用于css选择器目标的父元素将会丢失。如果有很多带有很多样式的子节点，这将导致一些延迟。

理想情况下，你应该有一个打印样式表，但这是为用例，没有打印样式表插入，你希望打印在屏幕上看到。

如果您在此页的浏览器控制台中复制以下项目，它将打印此页上的所有代码片段。

+function() {
    /**
     * copied from  https://stackoverflow.com/questions/19784064/set-javascript-computed-style-from-one-element-to-another
     * @author Adi Darachi https://stackoverflow.com/users/2318881/adi-darachi
     */
    var copyComputedStyle = function(from,to){
        var computed_style_object = false;
        //trying to figure out which style object we need to use depense on the browser support
        //so we try until we have one
        computed_style_object = from.currentStyle || document.defaultView.getComputedStyle(from,null);

        //if the browser dose not support both methods we will return null
        if(!computed_style_object) return null;

            var stylePropertyValid = function(name,value){
                        //checking that the value is not a undefined
                return typeof value !== 'undefined' &&
                        //checking that the value is not a object
                        typeof value !== 'object' &&
                        //checking that the value is not a function
                        typeof value !== 'function' &&
                        //checking that we dosent have empty string
                        value.length > 0 &&
                        //checking that the property is not int index ( happens on some browser
                        value != parseInt(value)

            };

        //we iterating the computed style object and compy the style props and the values
        for(property in computed_style_object)
        {
            //checking if the property and value we get are valid sinse browser have different implementations
                if(stylePropertyValid(property,computed_style_object[property]))
                {
                    //applying the style property to the target element
                        to.style[property] = computed_style_object[property];

                }   
        }   

    };


    // Copy over all relevant styles to preserve styling, work the way down the children tree.
    var buildChild = function(masterList, childList) {
        for(c=0; c<masterList.length; c++) {
           var master = masterList[c];
           var child = childList[c];
           copyComputedStyle(master, child);
           if(master.children && master.children.length > 0) {
               buildChild(master.children, child.children);
           }
        }
    }

    /** select elements to print with query selector **/
    var printSelection = function(querySelector) {
        // Create an iframe to make sure everything is clean and ordered.
        var iframe = document.createElement('iframe');
        // Give it enough dimension so you can visually check when modifying.
        iframe.width = document.width;
        iframe.height = document.height;
        // Add it to the current document to be sure it has the internal objects set up.
        document.body.append(iframe);

        var nodes = document.querySelectorAll(querySelector);
        if(!nodes || nodes.length == 0) {
           console.error('Printing Faillure: Nothing to print. Please check your querySelector');
           return;
        }

        for(i=0; i < nodes.length; i++) {

            // Get the node you wish to print.
            var origNode = nodes[i];

            // Clone it and all it's children
            var node = origNode.cloneNode(true);

            // Copy the base style.
            copyComputedStyle(origNode, node);

            if(origNode.children && origNode.children.length > 0) {
                buildChild(origNode.children, node.children);
            }

            // Add the styled clone to the iframe. using contentWindow.document since it seems the be the most widely supported version.

            iframe.contentWindow.document.body.append(node);
        }
        // Print the window
        iframe.contentWindow.print();

        // Give the browser a second to gather the data then remove the iframe.
        window.setTimeout(function() {iframe.parentNode.removeChild(iframe)}, 1000);
    }
window.printSelection = printSelection;
}();
printSelection('.default.prettyprint.prettyprinted')

我修改了@BillPaetski答案使用querySelector，添加可选的CSS，删除强制H1标签，并使标题可选地指定或从窗口拉出。它也不再自动打印，并公开内部内容，以便它们可以在包装器函数中切换或随你喜欢。

仅有的两个私有变量是tmpWindow和tmpDoc，尽管我相信标题，css和elem访问可能会有所不同，但应该假设所有函数参数都是私有的。

function PrintElem(elem, title, css) {
    var tmpWindow = window.open('', 'PRINT', 'height=400,width=600');
    var tmpDoc = tmpWindow.document;

    title = title || document.title;
    css = css || "";

    this.setTitle = function(newTitle) {
        title = newTitle || document.title;
    };

    this.setCSS = function(newCSS) {
        css = newCSS || "";
    };

    this.basicHtml5 = function(innerHTML) {
        return '<!doctype html><html>'+(innerHTML || "")+'</html>';
    };

    this.htmlHead = function(innerHTML) {
        return '<head>'+(innerHTML || "")+'</head>';
    };

    this.htmlTitle = function(title) {
        return '<title>'+(title || "")+'</title>';
    };

    this.styleTag = function(innerHTML) {
        return '<style>'+(innerHTML || "")+'</style>';
    };

    this.htmlBody = function(innerHTML) {
        return '<body>'+(innerHTML || "")+'</body>';
    };

    this.build = function() {
        tmpDoc.write(
            this.basicHtml5(
                this.htmlHead(
                    this.htmlTitle(title) + this.styleTag(css)
                ) + this.htmlBody(
                    document.querySelector(elem).innerHTML
                )
            )
        );
        tmpDoc.close(); // necessary for IE >= 10
    };

    this.print = function() {
        tmpWindow.focus(); // necessary for IE >= 10*/
        tmpWindow.print();
        tmpWindow.close();
    };

    this.build();
    return this;
}

DOMPrinter = PrintElem('#app-container');
DOMPrinter.print();

虽然@BC的答案最好打印一页。

但要打印多页A4大小的同时按ctrl+P以下解决方案可能会有所帮助。

@media print{
html *{
    height:0px!important;
    width:0px !important;
    margin: 0px !important;
    padding: 0px !important;
    min-height: 0px !important;
    line-height: 0px !important;
    overflow: visible !important;
    visibility: hidden ;


}


/*assing myPagesClass to every div you want to print on single separate A4 page*/

 body .myPagesClass {
    z-index: 100 !important;
    visibility: visible !important;
    position: relative !important;
    display: block !important;
    background-color: lightgray !important;
    height: 297mm !important;
    width: 211mm !important;
    position: relative !important;

    padding: 0px;
    top: 0 !important;
    left: 0 !important;
    margin: 0 !important;
    orphans: 0!important;
    widows: 0!important;
    overflow: visible !important;
    page-break-after: always;

}
@page{
    size: A4;
    margin: 0mm ;
    orphans: 0!important;
    widows: 0!important;
}}

如果你想拥有原始文档的所有样式(包括内联样式)，你可以使用这种方法。

复制完整的文档 将body替换为要打印的元素。

实现:

class PrintUtil {
  static printDiv(elementId) {
    let printElement = document.getElementById(elementId);
    var printWindow = window.open('', 'PRINT');
    printWindow.document.write(document.documentElement.innerHTML);
    setTimeout(() => { // Needed for large documents
      printWindow.document.body.style.margin = '0 0';
      printWindow.document.body.innerHTML = printElement.outerHTML;
      printWindow.document.close(); // necessary for IE >= 10
      printWindow.focus(); // necessary for IE >= 10*/
      printWindow.print();
      printWindow.close();
    }, 1000)
  }   
}

我编写了一个插件来解决这种情况。我对现有的插件不满意，开始做一些更广泛/可配置的东西。

https://github.com/jasonday/printThis

只需使用PrintJS

let printjs = document.createElement("script");
printjs.src = "https://printjs-4de6.kxcdn.com/print.min.js";
document.body.appendChild(printjs);

printjs.onload = function (){
    printJS('id_of_div_you_want_to_print', 'html');
}