在php分页中保留post变量

<form method="POST" action="process.php">
  <input type="text" name="username">
  <input type="submit" value="Submit">
</form>

session_start();
if ($_SERVER['REQUEST_METHOD'] === 'POST') {
  $_SESSION['post_data'] = $_POST;
  // 处理其他逻辑
}

session_start();
if (isset($_SESSION['post_data'])) {
  $postData = $_SESSION['post_data'];
  unset($_SESSION['post_data']); // 清除会话中的POST数据
} else {
  $postData = array(); // 如果没有POST数据，则创建一个空数组
}

<form method="POST" action="process.php">
  <input type="text" name="username" value="<?php echo isset($postData['username']) ? $postData['username'] : ''; ?>">
  <input type="submit" value="Submit">
</form>