我添加了两个用户元，它们的功能非常好。现在，我想根据输入显示一条警告消息。我通过一个get变量（名为meta_warning 通过add_query_arg) 并相应显示消息。但是在刷新页面时，消息会重复（因为get变量直接在url中传递）。

我注意到wordpress使用了一个类似的变量（updated=1）来显示“User updated”消息。但url中不存在此变量。我如何才能做到这一点？这样我的警告消息在重新加载时不会重复。

memberAdmin.class.php

<?php
class memberAdmin
{
public function __construct()
{
add_action(\'load-user-edit.php\', array($this, \'member_meta_message\'), 10, 2);
add_action(\'show_user_profile\', array($this, \'member_meta_form\'));
add_action(\'edit_user_profile\', array($this, \'member_meta_form\'));
add_action(\'edit_user_profile_update\',  array($this, \'member_meta_add\'));
}

function member_meta_message()
{
    /* URL: http://localhost/wordpress/wp-admin/user-edit.php?
            user_id=6&
            wp_http_referer=/wordpress/wp-admin/users.php&
            meta_warning[0]=postcode
    */
    echo \'<pre>\';
    print_r($_GET);
    echo \'</pre>\';
    /************* OUTPUT *******************

    Array
    (
        [user_id] => 6
        [updated] => 1
        [wp_http_referer] => /wordpress/wp-admin/users.php
        [meta_warning] => Array
        (
            [0] => postcode
        )
    )

    ********************************************/
    if(!empty($_GET[\'meta_warning\']))
    {
        echo \'<div class="notice notice-warning is-dismissible"><p>\'.implode(\', \', $_GET[\'meta_warning\']).\' fields not updated</p></div>\';
        // Message displayed correctly
    }
}

function member_meta_add($user_id)
{
    $err_fields = array();

    if (isset($_POST[\'submit\'])) {
        $membObj = new stdClass();

        $membObj->postcode= (isset($_POST[\'postcode\'])) ? strip_tags($_POST[\'postcode\']) : \'\';
        if (!empty($membObj->postcode))
            update_user_meta($user_id, \'postcode\', $membObj->postcode);
        else
            array_push($err_fields, \'postcode\');

        $membObj->mobile = (isset($_POST[\'mobile\'])) ? strip_tags($_POST[\'mobile\']) : \'\';
        if (!empty($membObj->mobile))
            update_user_meta($user_id, \'mobile\', $membObj->mobile);
        else
            array_push($err_fields, \'mobile\');

        if (!empty($err_fields)) {
            add_filter( \'wp_redirect\', function( $location ) use ( $err_fields ) {
                return add_query_arg( \'meta_warning\', $err_fields, $location );
            });
        }
    }
}

function member_meta_form($user)
{
    require_once ABSPATH . \'/lib/myWPUtilObj.class.php\';
    $myWPUtilObj= new myWPUtilObj();
    $umetas = $myWPUtilObj->get_member_meta($user->ID);
?>
<h3><?php _e("Member information", "blank"); ?></h3>
<table class="form-table" role="presentation">
<tr>
    <th><label for="postcode"><?php _e("Postal code"); ?></label></th>
    <td><input type="text" name="postcode" id="postcode" value="<?php echo esc_attr($umetas->postcode); ?>" class="regular-text" required="required" /><br /></td>
</tr>
<tr>
    <th><label for="mobile"><?php _e("Mobile"); ?></label></th>
    <td><input type="text" name="mobile" id="mobile" value="<?php echo esc_attr($umetas->mobile); ?>" class="regular-text" required="required" /><br /></td>
</tr>
</table>
<?php
}
}
?>