Ajax异步传输与PHP实现交互
背景 前台页面两个select框,一个与学院关联,另一个与专业关联,现需要选择学院select框后,显示学院相关信息,且专业select下面仅有属于该学院的专业名称。也就是实现一个二级联动效果。 两个select里面分别定义onchange事件,事件中利用ajax的GET方法向后
背景
前台页面两个select框,一个与学院关联,另一个与专业关联,现需要选择学院select框后,显示学院相关信息,且专业select下面仅有属于该学院的专业名称。也就是实现一个二级联动效果。
两个select里面分别定义onchange事件,事件中利用ajax的GET方法向后台PHP递交信息,再将查询得到的信息echo出来或document.write。
注:代码参考了有位叫y0umer的博主写的。
<script type="text/javascript"> var XmlHttp; function createXmlHttpRequestObject(){ if(window.ActiveXobject){ // 判断是否是ie浏览器 try { // try开始 xmlhttp = new ActiveXobject("Microsoft.XMLHTTP"); // 使用ActiveX对象创建ajax }catch(e){ xmlHttp = false; } // try end }else{ //Chrome、FireFox等非ie内核 try{ xmlHttp = new XMLHttpRequest(); //视为非ie情况下 }catch(e){ xmlHttp = false; // 其他非主流浏览器 } } // 判断结束,如果创建成功则返回一个DOM对象,如果创建不成功则返回一个false if(xmlHttp) { return xmlHttp; }else{ alert("对象创建失败,请检查浏览器是否支持XmlHttpRequest!"); } } // 函数体 //学院下拉框事件 function showCollegeInfo(){ var selectIndex = document.getElementById("college").selectedIndex;//获得是第几个被选中了 var value = document.getElementById("college").options[selectIndex].value; if(value) { // 先创建一个对象实例 createXmlHttpRequestObject(); // 使用事件对象获取文本框ID的值 var vCollege = value; var url = "college.php?xy="+vCollege; //待发送URL url=encodeURI(url); xmlHttp.onreadystatechange=ajaxok; // 判断浏览器状态栏 (接收玩数据触发的事件) xmlHttp.open("GET",url,false); // GET向服务器端发送数据 xmlHttp.send(null); document.getElementById("collegeinfo").style.display="block";//显示学院信息的div }else{ document.getElementById("collegeinfo").style.display="none";//隐藏学院信息的div } } function ajaxok() { if(xmlHttp.readyState == 4 && xmlHttp.status==200) { document.getElementById("collegeinfo").innerHTML = xmlHttp.responseText; } } //专业下拉框事件 function showMajorInfo(){ var selectIndex = document.getElementById("major").selectedIndex;//获得是第几个被选中了 var value = document.getElementById("major").options[selectIndex].value; if(value) { // 先创建一个对象实例 createXmlHttpRequestObject(); // 使用事件对象获取文本框ID的值 var vMajor = value; var url = "major.php?zy="+vMajor; //待发送URL url=encodeURI(url); xmlHttp.onreadystatechange=ajaxok2; // 判断浏览器状态栏 (接收玩数据触发的事件) xmlHttp.open("GET",url,false); // GET向服务器端发送数据 xmlHttp.send(null); document.getElementById("majorinfo").style.display="block";//显示专业信息的div }else{ document.getElementById("majorinfo").style.display="none";//隐藏专业信息的div } } function ajaxok2() { if(xmlHttp.readyState == 4 && xmlHttp.status==200) { document.getElementById("majorinfo").innerHTML = xmlHttp.responseText; } } </script>

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