我创建了一个自定义帖子类型和元框，用于上载另一个图像。问题是，当我添加图像时，它会正确显示在后端的位置，当我更新它时，它也会显示相同的图像。

但是当我回到帖子修改它时，我找不到图片，如果我更新帖子，那么就没有图片显示。

<?php   
function hotels_meta_boxes() {
add_meta_box( \'hotels_form\', \'Hotels - Détails\', \'hotels_form\', \'hotels\', \'normal\', \'high\' );} function hotels_form() {
$post_id = get_the_ID();
$hotel_data = get_post_meta( $post_id, \'_hotel\', true );
$carte = ( empty( $hotel_data[\'carte\'] ) ) ? \'\' : $hotel_data[\'carte\'];
wp_nonce_field( \'hotels\', \'hotels\' );
?>  
    <h2 class="metaboxtitle">Coordonnées</h2>
<?php 
    global $post;

    $image_src = \'\';

    $image_id = get_post_meta( $post->ID, \'_hotel\', true );
    $image_src = wp_get_attachment_url( $image_id );

    ?>
    <img id="book_image" src="<?php echo $image_src ?>" style="max-width:100%;" />
    <input type="hidden" name="hotel[carte]" id="upload_image_id" value="<?php echo $image_id; ?>" />

        <a title="<?php esc_attr_e( \'Set book image\' ) ?>" href="#" id="set-book-image"><?php _e( \'Set book image\' ) ?></a>
        <a title="<?php esc_attr_e( \'Remove book image\' ) ?>" href="#" id="remove-book-image" style="<?php echo ( ! $image_id ? \'display:none;\' : \'\' ); ?>"><?php _e( \'Remove book image\' ) ?></a>
    </p>

    <script type="text/javascript">
    jQuery(document).ready(function($) {

        // save the send_to_editor handler function
        window.send_to_editor_default = window.send_to_editor;

        $(\'#set-book-image\').click(function(){

            // replace the default send_to_editor handler function with our own
            window.send_to_editor = window.attach_image;
            tb_show(\'\', \'media-upload.php?post_id=<?php echo $post->ID ?>&amp;type=image&amp;TB_iframe=true\');

            return false;
        });

        $(\'#remove-book-image\').click(function() {

            $(\'#upload_image_id\').val(\'\');
            $(\'img\').attr(\'src\', \'\');
            $(this).hide();

            return false;
        });

        // handler function which is invoked after the user selects an image from the gallery popup.
        // this function displays the image and sets the id so it can be persisted to the post meta
        window.attach_image = function(html) {

            // turn the returned image html into a hidden image element so we can easily pull the relevant attributes we need
            $(\'body\').append(\'<div id="temp_image">\' + html + \'</div>\');

            var img = $(\'#temp_image\').find(\'img\');

            imgurl   = img.attr(\'src\');
            imgclass = img.attr(\'class\');
            imgid    = parseInt(imgclass.replace(/\\D/g, \'\'), 10);

            $(\'#upload_image_id\').val(imgid);
            $(\'#remove-book-image\').show();

            $(\'img#book_image\').attr(\'src\', imgurl);
            try{tb_remove();}catch(e){};
            $(\'#temp_image\').remove();

            // restore the send_to_editor handler function
            window.send_to_editor = window.send_to_editor_default;

        }

    });
    </script>

</p>
<?php } add_action( \'save_post\', \'hotels_save_post\' );/*** Data validation and saving** This functions is attached to the \'save_post\' action hook.*/ function hotels_save_post( $post_id ) {
if ( defined( \'DOING_AUTOSAVE\' ) && DOING_AUTOSAVE )
    return;

if ( ! empty( $_POST[\'hotels\'] ) && ! wp_verify_nonce( $_POST[\'hotels\'], \'hotels\' ) )
    return;

if ( ! empty( $_POST[\'post_type\'] ) && \'page\' == $_POST[\'post_type\'] ) {
    if ( ! current_user_can( \'edit_page\', $post_id ) )
        return;
} else {
    if ( ! current_user_can( \'edit_post\', $post_id ) )
        return;
}

if ( ! wp_is_post_revision( $post_id ) && \'hotels\' == get_post_type( $post_id ) ) {
    remove_action( \'save_post\', \'hotels_save_post\' );

    wp_update_post( array(
        \'ID\' => $post_id,
    ) );

    add_action( \'save_post\', \'hotels_save_post\' );
}

if ( ! empty( $_POST[\'hotel\'] ) ) {
    $hotel_data[\'carte\'] = ( empty( $_POST[\'hotel\'][\'carte\'] ) ) ? \'\' : sanitize_text_field( $_POST[\'hotel\'][\'carte\'] );
    update_post_meta( $post_id, \'_hotel\', $hotel_data );
} else {
    delete_post_meta( $post_id, \'_hotel\' );
}} add_filter( \'manage_edit-hotels_columns\', \'hotels_edit_columns\' );/******************** and to show it i use *************************/if ( $query->have_posts() ) {
    while ( $query->have_posts() ) : $query->the_post();
        $post_id = get_the_ID();
        $hotel_data = get_post_meta( $post_id, \'_hotel\', true );
        $carte = ( empty( $hotel_data[\'carte\'] ) ) ? \'\' : $hotel_data[\'carte\'];
        $hotels .= \'<div class="hotel_map">\';
                $carte = ( empty( $hotel_data[\'carte\'] ) ) ? \'Map introuvable\' : $hotel_data[\'carte\'];
            $hotels .= \'<img src="\' . wp_get_attachment_url( $carte ) . \'" style="margin-top: 10px;"/>\' ;
            $hotels .= \'</div>\';//fin map
            endwhile;
    wp_reset_postdata();
}
else {
    echo \'Pas d\\\'hotels pour l\\\'instant\';
}
return $hotels;}