abstrak：<?php $user = json_decode($_POST['data']); $email = $user->email; $password = sha1($user->password); $pdo = new PDO('mysql:host=local
<?php
$user = json_decode($_POST['data']);
$email = $user->email;
$password = sha1($user->password);
$pdo = new PDO('mysql:host=localhost;dbname=php','root','root');
$sql = "SELECT COUNT(*) FROM `user` WHERE `email`='{$email}' AND `password`='{$password}' ";
$stmt = $pdo->prepare($sql);
$stmt->execute();
if ($stmt->fetchColumn(0) == 1) {
echo json_encode(['status'=>1,'msg'=>'登錄成功,正在跳轉(zhuǎn)...']) ;
exit;
} else {
echo json_encode(['status'=>0,'msg'=>'郵箱或密碼錯(cuò)誤,登錄失敗!']) ;
exit;
}數(shù)據(jù)庫(kù)操作還沒(méi)學(xué)，只能照抄
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Ajax實(shí)戰(zhàn):表單驗(yàn)證</title>
</head>
<body>
<h3>用戶登錄</h3>
<form>
<p>郵箱: <input type="email" name="email"></p>
<p>密碼: <input type="password" name="password"></p>
<p><button type="button">提交</button></p>
</form>
<script>
let btn = document.getElementsByTagName('button')[0];
btn.onclick = function () {
//1.創(chuàng)建xhr對(duì)象
let xhr = new XMLHttpRequest();
//2.監(jiān)聽(tīng)響應(yīng)狀態(tài)
xhr.onreadystatechange = function(){
if (xhr.readyState === 4) { // 準(zhǔn)備就緒
// 判斷響應(yīng)結(jié)果:
if (xhr.status === 200) {
// 響應(yīng)成功,通過(guò)xhr對(duì)象的responseText屬性可以獲取響應(yīng)的文本,此時(shí)是html文檔內(nèi)容
let p = document.createElement('p'); //創(chuàng)建新元素放返回的內(nèi)容
p.style.color = 'red';
let json = JSON.parse(xhr.responseText);
if (json.status === 1) {
p.innerHTML = json.msg;
} else if (json.status == 0) {
p.innerHTML = json.msg;
}
// 將響應(yīng)文本添加到新元素上
document.forms[0].appendChild(p); // 將新元素插入到當(dāng)前頁(yè)面中
btn.disabled = true;
setTimeout(function(){
document.forms[0].removeChild(p);
btn.disabled = false;
if (json.status == 1) {
location.href = 'admin.php';
}
},2000);
} else {
// 響應(yīng)失敗,并根據(jù)響應(yīng)碼判斷失敗原因
alert('響應(yīng)失敗'+xhr.status);
}
} else {
}
}
//3.設(shè)置請(qǐng)求參數(shù)
xhr.open('post','inc/check.php',true);
//4. 設(shè)置頭信息,將內(nèi)容類型設(shè)置為表單提交方式
xhr.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
//5.發(fā)送請(qǐng)求
let data = {
email: document.getElementsByName('email')[0].value,
password: document.getElementsByName('password')[0].value
};
// data = 'email='+data.email+'&password='+data.password;
let data_json=JSON.stringify(data);
xhr.send('data='+data_json);
}
</script>
</body>
</html>異步的特點(diǎn)：帶監(jiān)聽(tīng)環(huán)節(jié)，把要做的事情，放在監(jiān)聽(tīng)響應(yīng)狀態(tài)的函數(shù)中
不知道這么理解可以嗎
本案例還學(xué)習(xí)了js對(duì)象與json格式轉(zhuǎn)換
JSON.parse()解析json格式為js對(duì)象
JSON.stringify() JavaScript 值轉(zhuǎn)換為 JSON 字符串