我正在学习编码插件。

我试图在插件页面中创建一个表单，它可以发送邮件。

这是我的代码，但它不起作用（我没有收到电子邮件，也没有显示任何错误）。

add_action(\'admin_menu\', \'add_contact_us_page\');

function add_contact_us_page() {
     add_menu_page(
        __( \'Contact Us\', \'textdomain\' ),
        __( \'Contact Us\',\'textdomain\' ),
        \'manage_options\',
        \'support_form_page\',
        \'support_form\',
        \'\'
    );
}

 function support_form() {
     ?>
    <form action="" method="post" enctype="text/plain">
Name:<br>
<input type="text" name="name"><br>
E-mail:<br>
<input type="text" name="email"><br>
Message:<br>
<input type="text" name="message" size="50"><br><br>
<input type="submit" value="save">
</form>

<?php
 }


if ( isset($_POST["submit"])) {
    do_action(\'my_phpmailer_example\');
}

add_action( \'phpmailer_init\', \'my_phpmailer_example\' );
function my_phpmailer_example( $phpmailer ) {
    $phpmailer->isSMTP();     
    $phpmailer->Host = \'smtp.sendgrid.net\';
    $phpmailer->SMTPAuth = true; 
    $phpmailer->Port = 587;
    $phpmailer->Username = \'****\';
    $phpmailer->Password = \'****\';
    $phpmailer->SMTPSecure = "tls"; 
    $phpmailer->From = "you@yourdomail.com";
    $phpmailer->FromName = "Your Name";
    $phpmailer->Subject = "Subject Text";
    $phpmailer->Body = "<i>Mail body in HTML</i>";
    $phpmailer->AltBody = "This is the plain text version of the email content";
    $phpmailer->AddAddress("my@mail.com", "name"); 
    $phpmailer->SMTPDebug = true;
    $smtp_debug = ob_get_clean();
    if(!$phpmailer->send()) 
     {
    echo "Mailer Error: " . $phpmailer->ErrorInfo;
     } 
      else 
      {
     echo "Message has been sent successfully";
     echo $smtp_debug;
    }
}