直接看豆瓣代码啦

参数 .article-content 是指定复制那个元素内的内容，会自带版权信息
元素 article-title 是文章标题的标签

$(function(){
    _REVIEW_COPY_OPTIONS = {
        targetNode: ".article-content",
        handleCopy: function(e, t) {
                var n = ["内容来源-三三淘资源", "名称：" + $('.article-title').text(), "地址：" + $('.article-title > a').attr('href'), "\n\n"].join("\r\n");
                return n + e
        }
    },
    function (e) {
        if ("undefined" != typeof e) {
            var t = function() {
                return window.getSelection ? window.getSelection().toString() : document.selection && "Control" != document.selection.type ? document.selection.createRange().htmlText.replace(/<br>/gi, "\r\n") : ""
            },
            i = function(e, t) {
                if (e) try {
                    if (e.setData("Text", t), e.getData("Text").length > 0) return
                } catch(i) {
                    if (e.setData("text/plain", t), e.getData("text/plain").length > 0) return
                }
                var i = $("<div>").css({
                    position: "absolute",
                    left: "-99999px"
                }).appendTo("body");
                i.html(t),
                window.getSelection().selectAllChildren(i[0]),
                window.setTimeout(function() {
                    i.remove()
                },
                200)
            };
            $("body").delegate(e.targetNode, "copy cut",
            function(n) {
                var a = t();
                if (! (a.length <= 42)) {
                    var o = e.handleCopy && e.handleCopy(a, $(this)) || null;
                    if (o) {
                        n.preventDefault();
                        var r = n.originalEvent.clipboardData || window.clipboardData;
                        i(r, o)
                    }
                }
            })
        }
    } (_REVIEW_COPY_OPTIONS)
})