//WordPress后台文章列表、页面列表中显示对应ID
function fanly_post_id_column( $post_columns ) {
	$beginning = array_slice( $post_columns, 0 ,1 );
	$beginning[ 'postid' ] = __( 'ID', 'fanly' );
	$ending = array_slice( $post_columns, 1 );
	$post_columns = array_merge( $beginning, $ending );
	return $post_columns;
}
add_filter( 'manage_posts_columns', 'fanly_post_id_column' );//添加文章列表页ID标题
add_filter( 'manage_pages_columns', 'fanly_post_id_column' );//添加页面列表页....
 
function fanly_posts_id_column( $col, $val ) {
	if( $col == 'postid' ) echo $val;
}
add_action( 'manage_posts_custom_column', 'fanly_posts_id_column', 10, 2 );//添加文章列表页ID列数值
add_action( 'manage_pages_custom_column', 'fanly_posts_id_column', 10, 2 );//添加页面列表页ID...
 
function fanly_posts_id_column_css() {
	echo '<style type="text/css">#postid { width: 50px; }</style>';//ID列宽度
}
add_action( 'admin_head-edit.php', 'fanly_posts_id_column_css' );