每次刷新页面时如何解决发送电子邮件[重复]

Question

这些表单在提交后工作。但是在刷新页面后邮件一次又一次地发送。

<?php
$to = "abc.com";
$subject = "This is subject";
$message = "<b>This is HTML message.</b>";
$message .= "<h1>This is headline.</h1>";
$header = "From:mithlesh@rightturn.co.in \r\n";
$header .= "MIME-Version: 1.0\r\n";
$header .= "Content-type: text/html\r\n";
$retval = mail ($to,$subject,$message,$header);
if( $retval == true ) {
    echo "Message sent successfully...";
}else {
    echo "Message could not be sent...";
}
?>

Answer 1

有多种处理方式。

1) 请在邮件发送成功后编写以下代码。

if(!$retval->Send()) {
    header("Location: http://www.example.com");
    exit;
}

2) 如果这对您不起作用，请使用元刷新方法：

if(!$retval->Send()) {
    $to = "http://www.example.com";
    $url = $to;
    print "<meta HTTP-EQUIV=Refresh CONTENT=\"5; URL=$url\">";
    print "Thank you for your message.";
    exit;
}

3) 您也可以使用 cookie。 要使用 cookie，您必须创建一个具有当前时间戳值的令牌，并且每当您创建具有当前时间戳的 cookie 时，然后在页面刷新时比较这两个变量。但是 cookie 有以前的时间戳，而 token 有当前的时间戳，那么它将不匹配。

$token = time();
setcookie('formToken', $token, time() + 3600);

if(isset($_POST['submit'])){

    if($_POST['token'] != $_COOKIE['formToken']){
        // die("Sorry");

        $error_list .= '<li>You can not submit this form twice.</li>';

        echo $error_list;
        echo 'Thank you, your message has been sent. You do not need resubmit it again.';
        exit;

    }

Source

Answer 2

您需要查看submit

if (isset($_POST['submit'])) {
}

所以你的代码是：

if (isset($_POST['submit'])) {
    $to = "abc.com";
    $subject = "This is subject";
    $message = "<b>This is HTML message.</b>";
    $message .= "<h1>This is headline.</h1>";
    $header = "From:mithlesh@rightturn.co.in \r\n";
    $header .= "MIME-Version: 1.0\r\n";
    $header .= "Content-type: text/html\r\n";
    $retval = mail ($to,$subject,$message,$header);
    if( $retval == true ) {
       echo "Message sent successfully...";
    }else {
       echo "Message could not be sent...";
    }
}

Answer 3

大多数邮件发送发生在特定事件或活动之后，就像表单提交或按钮单击一样。您需要设计具有相关字段的表单。然后您可以使用 isset() 或 !empty() 用于 $_POST 数组

if(!empty($_POST)){
    $to = "abc.com";
     $subject = "This is subject";
      $message = "<b>This is HTML message.</b>";
     $message .= "<h1>This is headline.</h1>";
     $header = "From:mithlesh@rightturn.co.in \r\n";
     $header .= "MIME-Version: 1.0\r\n";
     $header .= "Content-type: text/html\r\n";
     $retval = mail ($to,$subject,$message,$header);
     if( $retval == true ) {
        echo "Message sent successfully...";
     }else {
        echo "Message could not be sent...";
     }
}

Answer 4

将此代码放在 isset 提交按钮之外的 php 代码的开头

if(empty($_SESSION['key']) && !isset($_SESSION['key'])){
  $randomkey = rand(0,99999);
  $mykey = $_SESSION['key'] = $randomkey
}

它为 Session 设置了一个唯一的随机密钥。现在在表单字段中取一个隐藏字段

<input type="hidden" name="key" value="<?=$mykey?>">

现在提交

首先检查当前$mykey 是否与隐藏变量匹配 执行某些操作后未设置$mykey 所以它可以防止用户通过刷新页面多次添加数据。

希望对你有帮助... :-)