我有一个插件，它添加了一个带有文件上传表单的元框，该插件工作得很好，在元框中显示图像的链接（查看图像），加载文件，一旦发布帖子，它就会在主题中查看。（在我使用图像文件的示例中）：
<?php
/* Plugin Name: Custom Meta Upload Template*/
add_action('post_edit_form_tag', 'post_edit_form_tag');
function post_edit_form_tag() {
echo ' enctype="multipart/form-data"';
}
function custom_upload() {
add_meta_box( 'meta_upload', __( 'Upload Image', 'meta_upload_domain' ),'meta_upload_callback', 'post' );}
add_action( 'add_meta_boxes', 'custom_upload' );
function meta_upload_callback( $post ) {
global $post;
$custom = get_post_custom($post->ID);
$download_image01 = get_post_meta($post->ID, '_image01', true);
echo '<p><label for="document_file">Upload document:</label><br />';
echo '<input type="file" name="document_file" id="document_file" /></p>';
echo '</p>';
if(!empty($download_image01) && $download_image01 != '0') {
echo '<p><a href="' . wp_get_attachment_url($download_image01) . '">View Image</a></p>';
}
}
function meta_upload_save( $post_id ) {
global $post;
if(strtolower($_POST['post_type']) === 'page') {
if(!current_user_can('edit_page', $post_id)) {
return $post_id;
}
}
else {
if(!current_user_can('edit_post', $post_id)) {
return $post_id;
}
}
if(!empty($_FILES['document_file'])) {
$file = $_FILES['document_file'];
$upload = wp_handle_upload($file, array('test_form' => false));
if(!isset($upload['error']) && isset($upload['file'])) {
$title = $file['name'];
$ext = strrchr($title, '.');
$title = ($ext !== false) ? substr($title, 0, -strlen($ext)) : $title;
$attachment = array(
'post_mime_type' => 'image',
'post_title' => addslashes($title),
'post_content' => '',
'post_status' => 'inherit',
'post_parent' => $post->ID
);
$attach_key = '_image01';
$attach_id = wp_insert_attachment($attachment, $upload['file']);
$existing_download = (int) get_post_meta($post->ID, $attach_key, true);
if(is_numeric($existing_download)) {
wp_delete_attachment($existing_download);
}
update_post_meta($post->ID, $attach_key, $attach_id);
}
}
}
add_action( 'save_post', 'meta_upload_save' );
他调用了主题文件：
<?php
$download_image01 = get_post_meta($post->ID, '_image01', true);
if(!empty($download_image01) && $download_image01 != '0') { ?>
<div class="section-content">
<img src="<?php echo wp_get_attachment_url($download_image01); ?>" alt="" />
</div>
<?php }?>
我重复一遍，插件工作，但问题是，我不能放置一个按钮或复选框来删除文件时，例如，我想编辑帖子，并删除文件，当然，链接"查看图像"消失
任何想法！！
每当您想要编辑这些字段时，echo自定义字段的值如下所示。。。
<input type="" value="<img src="<?php echo wp_get_attachment_url($download_image01); ?>" alt="" />">
当你编辑帖子时，它会得到值并向你显示上传的图片。
我不知道这是否有帮助，但当我删除自定义帖子时，我使用此代码排除附件：
add_action('before_delete_post', 'delete_all_attached_media');
function delete_all_attached_media($post_id)
{
if (get_post_type($post_id) == "your-custom-post-type") {
$attachments = get_attached_media('', $post_id);
foreach ($attachments as $attachment) {
wp_delete_attachment($attachment->ID, 'true');
}
}
}