Question

我有一个网页，在选择后显示内容，它包含一个带有提交按钮的表单。单击提交按钮后，我想在上一页中显示错误消息。这是代码：

    //form is sending email through action:"email.php". Code in php file:   
    mail ($to, $subject, $mess);

    //set the error session...(I left out the form validation code to simplify)
    $_SESSION["Login.Error"] = "Invalid credentials";

    //go back to previous page with all previous selections
    $previousPage = $_SERVER['HTTP_REFERER'];
    header("Location: $previousPage");

在表单中，我添加了以下代码以显示错误消息：

<p class="form-text text-muted">Error Message: 
   <?php if(isset($_SESSION['Login.Error']))  {
   echo $_SESSION['Login.Error'];
   unset($_SESSION['Login.Error']); }
   ?> 
</p>

按下提交后，上一页加载正常，但错误信息没有显示，所以$ _SESSION我猜错了。或者这与$ _SERVER ['HTTP_REFERER']有关吗？有人可以帮忙吗？

Answer 1

您可以使用session_start（）;

   session_start();

   mail ($to, $subject, $mess);

  //set the error session...(I left out the form validation code to simplify)
  $_SESSION["Login.Error"] = "Invalid credentials";

  //go back to previous page with all previous selections
  $previousPage = $_SERVER['HTTP_REFERER'];
  header("Location: $previousPage")

/ * referer page * /

   <?php session_start();?>

  <p class="form-text text-muted">Error Message: 
         <?php if(isset($_SESSION['Login.Error']))  {
          echo $_SESSION['Login.Error'];
          unset($_SESSION['Login.Error']); }
  ?> 
  </p>

Answer 2

您需要按照以下代码启动会话。

<?php 
    session_start();
    mail ($to, $subject, $mess);

    $_SESSION["Login.Error"] = "Invalid credentials";
    $previousPage = $_SERVER['HTTP_REFERER'];
    header("Location: $previousPage");
?>

在表单中，我添加了以下代码以显示错误消息：

<p class="form-text text-muted">Error Message: 
   <?php 
   session_start();
   if(isset($_SESSION['Login.Error']))  {
       echo $_SESSION['Login.Error'];
       unset($_SESSION['Login.Error']);
   }
   ?> 
</p>

在php中提交表单后如何显示错误消息？

2 个答案: