reg.html
<!DOCTYPEHTML> <html> <head> <title>ajax</title> <Metacharset="utf-8"/> <scripttype="text/javascript"> varhttpAjax=newXMLHttpRequest(); functioncheckUser(uname){ if(uname==""){ returnfalse; } httpAjax.onreadystatechange=function(){ if(httpAjax.readyState==4&&httpAjax.status==200){ varres=httpAjax.responseText; res=eval("("+res+")"); varsp=document.getElementById("sp"); if(res.status==1){ sp.innerHTML="<fontcolor='red'>"+res.info+"</font>"; var_html=""; for(variinres['data']){ _html+="<p>"+res['data'][i]+"</p>" } varmyobject=document.getElementById('mydiv'); myobject.innerHTML=_html; }else{ sp.innerHTML="<fontcolor='green'>"+res.info+"</font>"; } } } httpAjax.open("post","user.PHP",true); httpAjax.setRequestHeader("content-TYPE","application/x-www-form-urlencoded"); vardata="uname="+uname;//user.PHP?uname="1"&pwd="123","uname="是参数,+是连接参数连接变量的用的，uname是js中的一个不带$的变量，也就是值 httpAjax.send(data); } </script> </head> <body> <inputtype="text"id="username"class="username"name="username"onchange="checkUser(this.value)"/><spanid="sp"></span> <divid="mydiv"style="width:200px;height:200px;border:1pxredsolid"> </div> </body> </html>
user.PHP
<?PHP header("content-type:text/html;charset=utf-8"); $pdo=newPDO("MysqL:host=localhost;dbname=tk106","root",""); $pdo->exec("setnamesutf8"); $uname=$_REQUEST["uname"];//post传值，这里要改为REQUEST $sql="select*fromstu_infowheresname='".$uname."'"; $data=$pdo->query($sql)->fetch(PDO::FETCH_ASSOC); if($data){ $list['status']=1; $list['info']="已经注册"; $list['data']=$data; echojson_encode($list); }else{ $list['status']=0; $list['info']="未注册"; $list['data']==""; echojson_encode($list); } ?>原文链接：https://www.f2er.com/ajax/162703.html
