以下代碼如果需要在你本地跑起來：
Ⅰ.需要apache服務(wù)，并把php代碼丟進(jìn)去指定位置
Ⅱ.將下面http://www.test.com/day05/jiekou.php地址，改成自己指定位置的域名或ip
1.從一段簡易代碼說起
前端代碼
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>Document</title>
<!-- 導(dǎo)入axios -->
<script src="https://unpkg.com/axios/dist/axios.min.js"></script>
</head>
<body>
<!-- POST 請求 -->
<form method="post">
<p>用戶名:<input id="username" type="text" name="username" value="admin"> </p>
<br />
<p>密 碼:<input id="password" type="text" name="password" value="123456"> </p>
<br />
<p><input id="btn" type="submit" value="登錄" /></p>
</form>
</body>
<script>
document.getElementById("btn").onclick = function () {
//獲取用戶輸入的登錄信息
let username = document.getElementById('username').value;
let password = document.getElementById('password').value;
//不處理的數(shù)據(jù)對象
let data = {
username: username,
password: password
};
console.log(data);//{username: "admin", password: "123456"}
//阻止submit默認(rèn)行為：表單提交刷新頁面
event.preventDefault();
//提交請求獲取響應(yīng)數(shù)據(jù)
axios.post("http://www.test.com/day05/jiekou.php", data).then(res => {
console.log(res);
}).catch(err => {
console.log(err);
})
}
</script>
</html>
php接口代碼
<?php
// 制定允許其他域名訪問
header("Access-Control-Allow-Origin:*");
// 允許的響應(yīng)類型
header('Access-Control-Allow-Methods: GET, POST, PUT,DELETE,OPTIONS,PATCH');
// 響應(yīng)頭設(shè)置
header("Access-Control-Allow-Headers: Origin, X-Requested-With, Content-Type, Accept, Authorization");
// 獲取form表單值
$username = $_POST['username'];
$password = $_POST['password'];
// 判斷form表單中key
if(isset($_POST['username']) && isset($_POST['password'])){
// 判斷username和password
if($username == "admin" && $password == "123456"){
$result = array("success" => 1, "code" => 101, "data" => array("username" => $username, "password" => $password));
}else{
$result = array("success" => 0, "code" => 103, "data" => null);
}
}else{
$result = array("success" => 0, "code" => 100, "data" => null);
}
// 將錯誤信息(數(shù)組)轉(zhuǎn)換成json類型,返回前端
echo(json_encode($result));
?>
結(jié)果：運(yùn)行失敗，無法獲取響應(yīng)數(shù)據(jù)
1.png
2.解決：
方法Ⅰ.引入qs模塊處理數(shù)據(jù):修改上面的html代碼
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>Document</title>
<!-- 導(dǎo)入axios -->
<script src="https://unpkg.com/axios/dist/axios.min.js"></script>
<!-- 導(dǎo)入qs -->
<script src="https://cdn.bootcss.com/qs/6.5.2/qs.min.js"></script>
</head>
<body>
<!-- POST 請求 -->
<form method="post">
<p>用戶名:<input id="username" type="text" name="username" value="admin"> </p>
<br />
<p>密 碼:<input id="password" type="text" name="password" value="123456"> </p>
<br />
<p><input id="btn" type="submit" value="登錄" /></p>
</form>
</body>
<script>
document.getElementById("btn").onclick = function () {
//獲取用戶輸入的登錄信息
let username = document.getElementById('username').value;
let password = document.getElementById('password').value;
// 用qs處理數(shù)據(jù)對象
//qs的原理：就是將對象轉(zhuǎn)變成字符串拼接到url上再發(fā)post請求
let data = Qs.stringify({
username: username,
password: password
});
console.log(data);//username=admin&password=123456
//阻止submit默認(rèn)行為：表單提交刷新頁面
event.preventDefault();
//提交請求獲取響應(yīng)數(shù)據(jù)
axios.post("http://www.test.com/day05/jiekou.php", data).then(res => {
console.log(res);
}).catch(err => {
console.log(err);
})
}
</script>
</html>
方法Ⅱ.后端開放options請求跨域，并用對應(yīng)的方法獲取options提交的復(fù)雜數(shù)據(jù)
<?php
// 制定允許其他域名訪問
header("Access-Control-Allow-Origin:*");
// 響應(yīng)類型
header('Access-Control-Allow-Methods: GET, POST, PUT,DELETE,OPTIONS,PATCH');
// 響應(yīng)頭設(shè)置
header("Access-Control-Allow-Headers: Origin, X-Requested-With, Content-Type, Accept, Authorization");
//如果是options請求败匹，就結(jié)束執(zhí)行下面語句
if($_SERVER['REQUEST_METHOD']=='OPTIONS'){
//exit是用來結(jié)束程序執(zhí)行的,如果參數(shù)是字符串撮胧，PHP將會直接把字符串輸出桨踪，
//如果參數(shù)是整型（范圍是0-254），那個參數(shù)將會被作為結(jié)束狀態(tài)使用芹啥。
exit('options類型的請求锻离，結(jié)束');
}
//option請求無法用常規(guī)方法($_GET, $_POST, $_REQUEST)獲取請求參數(shù)
$option_data_str = file_get_contents("php://input");
$option_data = json_decode($option_data_str,true);
$username = isset($option_data['username'])?$option_data['username']:"";
$password = isset($option_data['password'])?$option_data['password']:"";
// 判斷form表單中key
if(isset($username) && isset($password)){
// 判斷username和password
if($username == "admin" && $password == "123456"){
$result = array("success" => 1, "code" => 101, "data" => array("username" => $username, "password" => $password));
}else{
$result = array("success" => 0, "code" => 103, "data" => null);
}
}else{
$result = array("success" => 0, "code" => 100, "data" => null);
}
// 將錯誤信息(數(shù)組)轉(zhuǎn)換成json類型,返回前端
echo(json_encode($result));
?>
小結(jié)：：
Ⅰ.個人是比較傾向于由后端來解決（前端還要引入qs插件，沒什么必要）
Ⅱ.在vue里面使用qs的步驟
?qs是一個npm倉庫所管理的包,可通過npm install qs命令進(jìn)行安裝.
傳送門[https://www.npmjs.com/package/qs](https://www.npmjs.com/package/qs)
qs.parse()將URL解析成對象的形式
qs.stringify()將對象 序列化成URL的形式墓怀，以&進(jìn)行拼接（我們大都用到這個）
?在全局main.js里引入qs并配置方法到原型上
import qs from 'qs';
Vue.prototype.$qs = qs;
?在所有的vue實(shí)例組件里都可以直接用this.$qs.stringify(要處理的數(shù)據(jù))汽纠，進(jìn)行數(shù)據(jù)轉(zhuǎn)換
