WordPress函数wp_delete_attachment()

WordPress函数wp_delete_attachment()代码实现通过id进行删除附件

用法：

<?php wp_delete_attachment( $attachmentid, $force_delete ); ?>

参数：

$attachmentid

(integer) (必填) 要删除的附件ID

默认值:None

$force_delete

(bool) (可选) 是否绕过回收站并强制删除

默认值: false

源文件：

/**   * Trash or delete an attachment.   *   * When an attachment is permanently deleted, the file will also be removed.   * Deletion removes all post meta fields, taxonomy, comments, etc. associated   * with the attachment (except the main post).   *   * The attachment is moved to the trash instead of permanently deleted unless trash   * for media is disabled, item is already in the trash, or $force_delete is true.   *   * @since 2.0.0   *   * @global wpdb $wpdb WordPress database abstraction object.   *   * @param int  $post_id      Attachment ID.   * @param bool $force_delete Optional. Whether to bypass trash and force deletion.   *                           Default false.   * @return mixed False on failure. Post data on success.   */  function wp_delete_attachment( $post_id, $force_delete = false ) {  	global $wpdb;    	if ( !$post = $wpdb->get_row( $wpdb->prepare("SELECT * FROM $wpdb->posts WHERE ID = %d", $post_id) ) )  		return $post;    	if ( 'attachment' != $post->post_type )  		return false;    	if ( !$force_delete && EMPTY_TRASH_DAYS && MEDIA_TRASH && 'trash' != $post->post_status )  		return wp_trash_post( $post_id );    	delete_post_meta($post_id, '_wp_trash_meta_status');  	delete_post_meta($post_id, '_wp_trash_meta_time');    	$meta = wp_get_attachment_metadata( $post_id );  	$backup_sizes = get_post_meta( $post->ID, '_wp_attachment_backup_sizes', true );  	$file = get_attached_file( $post_id );    	if ( is_multisite() )  		delete_transient( 'dirsize_cache' );    	/**  	 * Fires before an attachment is deleted, at the start of wp_delete_attachment().  	 *  	 * @since 2.0.0  	 *  	 * @param int $post_id Attachment ID.  	 */  	do_action( 'delete_attachment', $post_id );    	wp_delete_object_term_relationships($post_id, array('category', 'post_tag'));  	wp_delete_object_term_relationships($post_id, get_object_taxonomies($post->post_type));    	// Delete all for any posts.  	delete_metadata( 'post', null, '_thumbnail_id', $post_id, true );    	$comment_ids = $wpdb->get_col( $wpdb->prepare( "SELECT comment_ID FROM $wpdb->comments WHERE comment_post_ID = %d", $post_id ));  	foreach ( $comment_ids as $comment_id )  		wp_delete_comment( $comment_id, true );    	$post_meta_ids = $wpdb->get_col( $wpdb->prepare( "SELECT meta_id FROM $wpdb->postmeta WHERE post_id = %d ", $post_id ));  	foreach ( $post_meta_ids as $mid )  		delete_metadata_by_mid( 'post', $mid );    	/** This action is documented in wp-includes/post.php */  	do_action( 'delete_post', $post_id );  	$result = $wpdb->delete( $wpdb->posts, array( 'ID' => $post_id ) );  	if ( ! $result ) {  		return false;  	}  	/** This action is documented in wp-includes/post.php */  	do_action( 'deleted_post', $post_id );    	$uploadpath = wp_upload_dir();    	if ( ! empty($meta['thumb']) ) {  		// Don't delete the thumb if another attachment uses it.  		if (! $wpdb->get_row( $wpdb->prepare( "SELECT meta_id FROM $wpdb->postmeta WHERE meta_key = '_wp_attachment_metadata' AND meta_value LIKE %s AND post_id <> %d", '%' . $wpdb->esc_like( $meta['thumb'] ) . '%', $post_id)) ) {  			$thumbfile = str_replace(basename($file), $meta['thumb'], $file);  			/** This filter is documented in wp-includes/functions.php */  			$thumbfile = apply_filters( 'wp_delete_file', $thumbfile );  			@ unlink( path_join($uploadpath['basedir'], $thumbfile) );  		}  	}    	// Remove intermediate and backup images if there are any.  	if ( isset( $meta['sizes'] ) && is_array( $meta['sizes'] ) ) {  		foreach ( $meta['sizes'] as $size => $sizeinfo ) {  			$intermediate_file = str_replace( basename( $file ), $sizeinfo['file'], $file );  			/** This filter is documented in wp-includes/functions.php */  			$intermediate_file = apply_filters( 'wp_delete_file', $intermediate_file );  			@ unlink( path_join( $uploadpath['basedir'], $intermediate_file ) );  		}  	}    	if ( is_array($backup_sizes) ) {  		foreach ( $backup_sizes as $size ) {  			$del_file = path_join( dirname($meta['file']), $size['file'] );  			/** This filter is documented in wp-includes/functions.php */  			$del_file = apply_filters( 'wp_delete_file', $del_file );  			@ unlink( path_join($uploadpath['basedir'], $del_file) );  		}  	}    	wp_delete_file( $file );    	clean_post_cache( $post );    	return $post;  }