/*-----------------JS 代码------------------------*/
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title></title>
<script src="js/jquery-1.12.4.min.js"></script>
</head>
<body>
<p><input type="text" id="username" placeholder="用户名"/></p>
<p><input type="text" id="pwd" placeholder="密码"/><br></p>
<input type="button" id="regit" value="注册"/>
<script>
$(function(){
var username = $("#username");
username.blur(function(){
if(username.val()==''){
alert("用户名不能为空");
}else{
checkUsername(username.val());
}
});
function checkUsername(name){
$.ajax({
type:"post",
url:"demo1.php",
async:true,
data:{"type":"checkusername","username":name},
success:function(data){
var flag = JSON.parse(data);
if(flag == true){
alert("用户名重复");
}else{
alert("用户名可用");
}
}
});
}
})
$("#regi").click(function(){
var name = $("#username").val();
var pwd = $("#pwd").val();
$.ajax({
type:"post",
url:"demo1.php",
async:true,
data:{"type":"register","username":name,"password":pwd},
success:function(data){
alert(data);
}
});
})
</script>
</body>
</html>
/*-----------------PHP 代码------------------------*/
<?php
$type = $_POST["type"];
if(isset($type)){//存在为true
//检查用户名是否存在;
if($type == "checkusername"){
$flag = "";
$username = $_POST["username"];
$json = file_get_contents("user1.json"); //获取user1.json里的数据 json格式
$arr_json = json_decode($json,true);//将json格式的数据转化为数组类型的数据
for($i=0;$i<count($arr_json);$i++){ //获取数组长度
if($arr_json[$i]["name"] == $username){
$flag = true;
}
}
echo json_encode($flag); //echo 返回前台的值 json_encode 将数组类型转换为json类型的数据
}
//用户注册；即向json文件写入新注册的用户名和密码
if($type == "register"){
$flag = true;
$username = $_POST["username"];
$password = $_POST["password"];
$array = array("name" => $username,"pwd" => $password);
$json = file_get_contents("user1.json");
$arr_json = json_decode($json,true);
array_push($arr_json,$array);
$json = json_encode($arr_json);
file_put_contents("user1.json",$json);
echo json_encode($json); //将更新过的json文件中所有的用户返回（仅用于测试）
}
//用户登录；在json文件检查是否存在输入的用户名以及密码是否正确；
if($type == "login"){
$name = $_POST["username"];
$pwd = $_POST["pwd"];
$flag = "";
$json = file_get_contents("user.json");
$arr_json = json_decode($json,true);
for($i=0;$i<count($arr_json);$i++){
if($arr_json[$i]["name"] == $name && $arr_json[$i]["pwd"] == $pwd){
$flag = true;
}
}
echo json_encode($flag);
}
}
?>
/*---------------------随便来一json文件-----------------------*/
[
{
"name": "admin",
"pwd": "1234"
}, {
"name": "aaa",
"pwd": "3333"
}, {
"name": "q",
"pwd": "1112"
}, {
"name": "111",
"pwd": "qqq"
}, {
"name": "1234567",
"pwd": "qqq"
}
]
源代码见附件
