AJAX，按书上敲的代码，为什么不能实现？

蓝with黑 2015-08-29 02:13:32

哪位大神帮看看。只实现了图片替换成loading...,没有将内容加载过来。

//ajax

function getHTTPObject() {

    if (typeof XMLHttpRequest == "undefined")

        XMLHttpRequest = function () {

            try {

                return new ActiveXObject("Msxml2.XMLHTTP.6.0");

            }

            catch (e) {}

            try {

                return new ActiveXObject("Msxml2.XMLHTTP.3.0");

            }

            catch (e) {}

            try {

                return new ActiveXObject("Msxml2.XMLHTTP");

            }

            catch (e) {}

            return false;

        }

    return new XMLHttpRequest();

}

function displayAjaxLoading(element) {

    while (element.hasChildNodes()) {

        element.removeChild(element.lastChild);

    }

    var content = document.createElement("img");

    content.setAttribute("src","image/ajax-loader.gif");

    content.setAttribute("alt", "loading...");

    element.appendChild(content);

}

function submitFormWithAjax(whichform, thetarget) {

    var request = getHTTPObject();//调用函数，检测浏览器，并创建XMLHttpRequest;

    if (!request) return false;

    displayAjaxLoading(thetarget);//删除目标元素子元素，添加load图片

    var dataParts = [];

    var element;

    for (var i = 0; i < whichform.elements.length; i++) {

        element = whichform.elements[i];

        dataParts[i] = element.name + '=' + encodeURIComponent(element.value);

        //把表单的值组织成URL编码的字符串，以便通过Ajax请求发送

        //收集它们的名字和编码后的值。

        }

        var data = dataParts.join('&');

        request.open('POST', whichform.getAttribute('action'), true);

        request.setRequestHeader("Content-type", "application/x-www-form-urlencoded");

        //这个头部对于POST请求是必须的，它表示请求中包含URL编码的表单

        request.onreadystatechange = function () {

            if (request.readyState == 4) {

                if (request.status == 200 || request.status == 0) {

                    var matches = request.responseText.match(/<article> ([\s\S]+)<\/article>/);

                    if (matches.length > 0) {

                        thetarget.innerHTML = matches[1];

                    } else {

                        thetarget.innerHTML = '<p>Oops,there was an error.sorry</p>'

                    }

                } else {

                    thetarget.innerHTML = '<p>' + request.statusText + '</p>';

                }

            }

        };

    request.send(data);

    return true;

}