如何连接或链接到本地​​主机服务器地址在Android Studio

Question

我正在做一个Android的登录注册的教程由tonakami电视在youtube，我遇到了一个问题，其中Android应用程序无法更新或连接到数据库通过LOCALHOST XAMPP。一个星期，我坚持搜索所有可能的解决方案，但没有发现。也许你们可以帮我解决我的PHP文件问题（register.php和fetchuserdata.php），我也发现我在php文件中也有这个错误：mysqli_connect（）:(HY000/1044）：访问拒绝用户'my_user'@'localhost'到数据库'my_db'。我授予所有权限，但仍然无法连接，我不知道问题是从PHP文件，到android studio中的服务器还是XAMPP本地主机phpmyadmin的链接。谢谢 ！

Screenshot of Android Studio: highlighted link

Register.php

<?php 
$con=mysqli_connect("localhost","my_user","my_password","my_db"); 

$name = $_POST["name"]; 
$age = $_POST["age"]; 
$username = $_POST["username"]; 
$password = $_POST["password"]; 
$statement = mysqli_prepare($con, "INSERT INTO User (name, age, username, password) VALUES (?, ?, ?, ?)"); 
mysqli_stmt_bind_param($statement, "siss", $name, $age, $username, $password); 
mysqli_stmt_execute($statement); 
mysqli_stmt_close($statement); 
mysqli_close($con); 
?> 

FetchUserData.php

<?php 
$con=mysqli_connect("localhost","my_user","my_password","my_db"); 

$username = $_POST["username"]; 
$password = $_POST["password"]; 

$statement = mysqli_prepare($con, "SELECT * FROM User WHERE username = ? AND password = ?"); 
mysqli_stmt_bind_param($statement, "ss", $username, $password); 
mysqli_stmt_execute($statement); 

mysqli_stmt_store_result($statement); 
mysqli_stmt_bind_result($statement, $userID, $name, $age, $username,  $password); 

$user = array(); 

while(mysqli_stmt_fetch($statement)){ 
    $user["name"] = $name; 
    $user["age"] = $age; 
    $user["username"] = $username; 
    $user["password"] = $password; 
} 

echo json_encode($user); 
mysqli_close($con); 
?> 

Answer 1

而不是本地主机使用：http://10.0.2.2 Reference