网上找了好多现成的。结果没一个能成。只得自己动手。

(function($){    $.fn.fixHeader = {        init : function(obj){            var p = obj.parent();            //绑定事件            p.scroll(internalScroll);            //获取表格第一行            var head = obj.children("thead tr th:first");            if (!head || head.length == 0) {                var body = obj.children("tbody")[0];                head = $(body.children[0].children[0]);            }            var headHeight = head.height();            //创建新层            var headDiv = $("
     
").appendTo(p);            headDiv.css({                "width": p[0].scrollWidth,                "position":"absolute",                "top": p.offset().top,                "display" : "none",                "background-color":"#f5f5f5",                "height": headHeight            });            //克隆第一行            var table = $("
     ").appendTo(headDiv);            $(obj[0].attributes).each(function () {                if (this.name == "id" || this.name == "ID" || this.name == "Id") return true;                if (this.value.indexOf("background-color") > -1) {                    table.attr(this.name, this.value.replace(new RegExp("background-color", "g"),""));                } else {                    table.attr(this.name, this.value);                }            });            table.css("text-align", "center").css("background-color", null);            var tr = $("").appendTo(table);            if (body) {                $(body.children[0]).children().each(function() {                    var td = $("").appendTo(tr);                    td.css({                        "width" : $(this).width(),                        "font-size" : $(this).css("font-size"),                        "background-color" : $(this).css("background-color"),                        "font-weight" : "bold"                    });                    td.text($(this).text());                });                            }            //滚动事件            function internalScroll() {                var top = obj.scrollTop();                if (top <= 100 - headHeight) {                    headDiv.css("display","");                }else{                    headDiv.css("display","none");                }                $("#btnTest").val(top + " " + head.height());            }            $(window).resize(function() {                setTimeout(100, doResize());            });            function doResize() {                headDiv.css("width", p[0].scrollWidth);                var tbl = $("#tblFixHeader");                if (tbl && tbl.length == 1) {                    var line = obj.children().get(0).children[0];                    if (line) {                        var line2 = tbl.children().get(0).children[0];                        if (line2) {                            for (var i = 0; i < line.children.length; i++) {                                $(line2.children[i]).css("width", $(line.children[i]).css("width"));                            }                        }                    }                }            }        }    };})(jQuery);

好用，就拿走。