php+js+mysql设计的仿webQQ-聊天消息的发送与刷新

<12>消息的发送

Js文件

function sendMessage(friendEmail,chat,text){
        var xmlhttp;
        if(window.XMLHttpRequest){//code for IE7+, Firefox, Chrome, Opera, Safari
                xmlhttp=new XMLHttpRequest();
                if(xmlhttp.overrideMimeType){//设置MIME类别
                        xmlhttp.overrideMimeType("text/xml");
                        }
                }
        else{//code for IE6, IE5
                xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
                }
        var today=new Date();     //获取本地时间
        var y=today.getFullYear();
        var mo=today.getMonth()+1;    //因为js获取本地时间的月份的值的范围是0-11，所以在这里加1
        var d=today.getDate();
        var h=today.getHours();
        var mi=today.getMinutes();
        var s=today.getSeconds();
        var sendtime=y+"-"+mo+"-"+d+" "+h+":"+mi+":"+s;
        var url="sendMessage.php?friendEmail="+friendEmail.id+"&text="+text+"&sendtime="+sendtime;   //转到php文件来处理消息
        xmlhttp.open("GET",url,true);
        xmlhttp.onreadystatechange=function(){
                if (xmlhttp.readyState==4 && xmlhttp.status==200){
                        document.getElementById(chat).innerHTML+=xmlhttp.responseText;
                        var e=document.getElementById(chat);
                        e.scrollTop=e.scrollHeight;         //该语句使滚动条永远在最下面
                        }
                }
    xmlhttp.send(null);   
        }

PHP文件

<?php
session_start();
header('Content-Type:text/html;charset=GB2312');
include("conn.php");
$email=$_SESSION["email"];
$nickname=$_SESSION["nickname"];
$friendEmail=$_GET["friendEmail"];
$text=$_GET["text"];
$sendtime=$_GET["sendtime"];
$sql="insert into chats values(now(),'$email','$friendEmail','$text',0)";
if($result=mysql_query($sql))
  { 
    echo "<font color='BLUE'>".$nickname." [".$sendtime."]</font><br/>";
        echo $text;
        echo "<br/>";
  }
else
  {
    echo "消息写入数据库失败！";
  }
?>

<13>消息的刷新

Js文件

function refreshChatDiv(obj,chatDivID){
        var xmlhttp;
        if(window.XMLHttpRequest){//code for IE7+, Firefox, Chrome, Opera, Safari
                xmlhttp=new XMLHttpRequest();
                if(xmlhttp.overrideMimeType){//设置MIME类别
                        xmlhttp.overrideMimeType("text/xml");
                        }
                }
        else{//code for IE6, IE5
                xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
                }
 
        var url="refreshChatDiv.php?friendEmail="+obj.id;      //转到PHP文件去查询数据库中有没有新的消息
        xmlhttp.open("GET",url,true);
        xmlhttp.onreadystatechange=function(){
                if (xmlhttp.readyState==4 && xmlhttp.status==200){
                        document.getElementById(chatDivID).innerHTML+=xmlhttp.responseText;
                        var e=document.getElementById(chatDivID);
                        e.scrollTop=e.scrollHeight;
                        setTimeout(function() {refreshChatDiv(obj,chatDivID);},3000);    //每隔3秒检测一下有没有新的信息
                        }
                }
    xmlhttp.send(null);
        }

PHP文件

<?php
session_start();
header('Content-Type:text/html;charset=GB2312');
include("conn.php");
$email=$_SESSION["email"];
$friendEmail=$_GET["friendEmail"];
$sql="select nickname,message,chattime from chats,user where chats.speaker=user.email and speaker='".$friendEmail."' and rapper='".$email."' 
and messageState=0";
if($result=mysql_query($sql))
{   
        while($row=mysql_fetch_array($result))
                 {
                         echo "<font color='BLUE'>".$row["nickname"]." [".$row["chattime"]."]"."</font><br/>";
                         echo $row["message"];
                         echo "<br/>";
                 }
    $updateSQL="update chats set messageState=1 where speaker='".$friendEmail."' and rapper='".$email."'";
        mysql_query($updateSQL);
 }
?>

至此，关键的技术点都写出来啦，欢迎大家拍砖！（完）