我已經(jīng)解決這個(gè)問題有一段時(shí)間了，目前正在嘗試將我的 php 腳本轉(zhuǎn)換為 PDO，但在運(yùn)行 isset() 時(shí) $_POST 總是給我 null。我在 android 中的代碼與我的其他腳本一起工作得很好，但是當(dāng)我將每個(gè)項(xiàng)目上的 $_POST 更改為 $_REQUEST 并且鏈接看起來也不同時(shí)，這個(gè)代碼只能在郵遞員中工作。還值得一提的是 onResponse 和 onFailure 不會(huì)接收/打印任何消息。郵遞員網(wǎng)址http://123.456.7.89/Database/register.php?username=asdfasdf&password=lj4ioidfoislkjsf&email=jalenpauloiudf&tece=true&profilePicPath=aksdfjlakjdsfl&tokenId=as89gwbeg98sd當(dāng)前網(wǎng)址http://123.456.7.89/Database/register.php腳本<?php$servername = "localhost";$dbUsername = "root";$dbPassword = "password";$dbname = "Database";try {    $conn = new PDO("mysql:host=$servername;dbname=$dbname", $dbUsername, $dbPassword);    $conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);        $username = $_POST['username'];    $password = $_POST['password'];    $email = $_POST['email'];    $termsOfService = $_POST['termsOfService'];    $profilePicPath = $_POST['profilePicPath'];    $tokenId = $_POST['tokenId'];    $userId = uniqId();    //converting data    $termsOfService = $termsOfService ? 'true' : 'false';    //Username check    $emailForQuery = "%" . $_POST['email'] . "%";    $userIdForQuery = "%" . $userId . "%";    $usernameCheckQuery = $conn->prepare("SELECT email, userId FROM users WHERE email LIKE ? OR userId LIKE ? LIMIT 1");    $usernameCheckQuery->execute([$emailForQuery, $userIdForQuery]);     $usernameCheckQuery->fetch();