本篇通过一个实例介绍ajax与php结合使用的方式，可以下载该实例的源程序以便更好理解。压缩包中functions.js就是ajax核心代码了，所有的操作效果都是通过它来实现的。下文的代码解释都是提取自functions.js。
效果1. 当鼠标放在某日上时，如果当天有备忘录，则会显示出来，如下图：
//找到页面中taskbox对应
设置为可见
theObject = document.getElementById("taskbox");
theObject.style.visibility = "visible";
//初始化taskbox位置
var posx = 0;
var posy = 0;
//定位taskbox位置为鼠标位置
posx = e.clientX + document.body.scrollLeft;
posy = e.clientY + document.body.scrollTop;
theObject.style.left = posx + "px";
theObject.style.top = posy + "px";
//设置PHP请求页面
serverPage = "taskchecker.php?thedate=" + thedate;
//设置PHP返回数据替换位置
objID = "taskbox";
var obj = document.getElementById(objID);
//发送请求并加载返回数据
xmlhttp.open("GET", serverPage);
xmlhttp.onreadystatechange = function(){
if (xmlhttp.readyState == 4 && xmlhttp.status == 200){
obj.innerHTML = xmlhttp.responseText;
}
}
xmlhttp.send(null);
}
//定位页面中autocompletediv（显示检索姓名的标签）的
theObject = document.getElementById("taskbox");
theObject.style.visibility = "visible";
//初始化taskbox位置
var posx = 0;
var posy = 0;
//定位taskbox位置为鼠标位置
posx = e.clientX + document.body.scrollLeft;
posy = e.clientY + document.body.scrollTop;
theObject.style.left = posx + "px";
theObject.style.top = posy + "px";
//设置PHP请求页面
serverPage = "taskchecker.php?thedate=" + thedate;
//设置PHP返回数据替换位置
objID = "taskbox";
var obj = document.getElementById(objID);
//发送请求并加载返回数据
xmlhttp.open("GET", serverPage);
xmlhttp.onreadystatechange = function(){
if (xmlhttp.readyState == 4 && xmlhttp.status == 200){
obj.innerHTML = xmlhttp.responseText;
}
}
xmlhttp.send(null);
}
效果2. 当鼠标点击某日录入姓名时，系统会自动检索姓名是否存在，并可以通过选择填入姓名框中，如图：
Copy to Clipboard引用的内容：[www.bkjia.com] function autocomplete (thevalue, e){//定位页面中autocompletediv（显示检索姓名的标签）的
位置
theObject = document.getElementById("autocompletediv");
//设置为可见
theObject.style.visibility = "visible";
theObject.style.width = "152px";
//设置检索标签位置
var posx = 0;
var posy = 0;
posx = (findPosX (document.getElementById("yourname")) + 1);
posy = (findPosY (document.getElementById("yourname")) + 23);
theObject.style.left = posx + "px";
theObject.style.top = posy + "px";
//设定事件为键盘录入
var theextrachar = e.which;
if (theextrachar == undefined){
theextrachar = e.keyCode;
}
//设定加载检索名单位置
var objID = "autocompletediv";
//设定PHP请求页面，并将用户输入的姓名传值过去（同时考虑到Backspace作用）
if (theextrachar == 8){
if (thevalue.length == 1){
var serverPage = "autocomp.php";
}
else{
var serverPage = "autocomp.php" + "?sstring=" + thevalue.substr(0, (thevalue.length -1));
}
}
else{
var serverPage = "autocomp.php" + "?sstring=" + thevalue + String.fromCharCode(theextrachar);
}
//发送请求并加载返回数据
var obj = document.getElementById(objID);
xmlhttp.open("GET", serverPage);
xmlhttp.onreadystatechange = function() {
if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {
obj.innerHTML = xmlhttp.responseText;
}
}
xmlhttp.send(null);
}
theObject = document.getElementById("autocompletediv");
//设置为可见
theObject.style.visibility = "visible";
theObject.style.width = "152px";
//设置检索标签位置
var posx = 0;
var posy = 0;
posx = (findPosX (document.getElementById("yourname")) + 1);
posy = (findPosY (document.getElementById("yourname")) + 23);
theObject.style.left = posx + "px";
theObject.style.top = posy + "px";
//设定事件为键盘录入
var theextrachar = e.which;
if (theextrachar == undefined){
theextrachar = e.keyCode;
}
//设定加载检索名单位置
var objID = "autocompletediv";
//设定PHP请求页面，并将用户输入的姓名传值过去（同时考虑到Backspace作用）
if (theextrachar == 8){
if (thevalue.length == 1){
var serverPage = "autocomp.php";
}
else{
var serverPage = "autocomp.php" + "?sstring=" + thevalue.substr(0, (thevalue.length -1));
}
}
else{
var serverPage = "autocomp.php" + "?sstring=" + thevalue + String.fromCharCode(theextrachar);
}
//发送请求并加载返回数据
var obj = document.getElementById(objID);
xmlhttp.open("GET", serverPage);
xmlhttp.onreadystatechange = function() {
if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {
obj.innerHTML = xmlhttp.responseText;
}
}
xmlhttp.send(null);
}
源代码下载：Sample3.rar
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