ajxser

<script>

   <span
style=
"background-color: #c0c0c0;"> var xmlHttp;</span>//创建一个对象

    function queryDetail(id){

        if(window.ActiveXObject){

            xmlHttp = new ActiveXObject("MICROSOFT.XMLHTTP");

        }else if(window.XMLHttpRequest){

            xmlHttp = new XMLHttpRequest();

        }

        if(!xmlHttp){

            alert("没有获取到对象!");

            return;

        }

<span
style=
"background-color: #00ff00;">        //由于javascript是没有办法连接数据库的,所以,需要通过后台语言

        //结合来连接数据库,那么这里就是把js从界面获取的值,传递给后台程序

        //xmlHttp.open()其实也就是链接到一个后台程序,把值传递过去

        //这其实是第一步</span>

        xmlHttp<span style="background-color: #ff0000;">.open("GET","queryById.php?id="+id,true);</span>

<span
style=
"background-color: #00ff00;">        //这是第三步

        //这一步是一个回调函数,回调函数其实就和打电话代办事情是一个意思

        //这个回调函数其实就是状态改变的时候,js应该做什么事情</span>

        xmlHttp<span style="background-color: #ff0000;">.onreadystatechange = function()</span>{

            if(xmlHttp.readyState ==
4){

                if(xmlHttp.status ==
200){

                    var txt =
xmlHttp.responseText;

                    var show =
document.getElementById(
"show")

                    if(show){

                        show.innerHTML = "";

                        document.body.removeChild(show);

                    }else{

                        var d =
document.createElement(
"div");

                        d.id = "show";

                        d.style.cssText="width:200px;height:300px;border:1px solid red;";

                        var strs =
txt.split(
",");

                        alert(strs);

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

                            d.innerHTML += strs[i] + "<br/>";

                        }

                        document.body.appendChild(d);

                    }

                }

            }

        }

   <span
style=
"background-color: #00ff00;">     //注意,open()方法就仅仅只是打开了连接,并没有传递,所以需要send方法

        //这是第二步</span>

        xmlHttp.<span style="background-color: #ff0000;">send(null);</span>

    }

</script>

时间: 2024-10-05 18:02:18

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