我正在使用中的函数this 回答上载、附加，然后[设置\\u post\\u tumbnail][2]/将特色图像添加到我通过RSS源创建的帖子。

我运行了一个测试，输出显示附件ID与我的缩略图ID匹配。我在媒体库中进行了检查，它正在根据get_post_thumbnail_id 但是the problem is 我的特色图像元框没有通过仪表板显示图像，或者在我的模板中使用[获取帖子缩略图][4]时也没有显示图像。

我在这里遗漏了什么步骤吗？代码主要来自上面链接的答案，最后还有一些测试。

global $wp_query;
                wp_insert_post($my_post); // create a new post
                $post_id = $wp_query->post->ID;  // get the ID for the new post


                $image_url = $thumbnail;
                $upload_dir = wp_upload_dir();
                $image_data = file_get_contents($image_url);
                $filename = basename($image_url);
                if(wp_mkdir_p($upload_dir[\'path\']))
                    $file = $upload_dir[\'path\'] . \'/\' . $filename;
                else
                    $file = $upload_dir[\'basedir\'] . \'/\' . $filename;
                file_put_contents($file, $image_data);

                $wp_filetype = wp_check_filetype($filename, null );
                $attachment = array(
                    \'post_mime_type\' => $wp_filetype[\'type\'],
                    \'post_title\' => sanitize_file_name($filename),
                    \'post_content\' => \'\',
                    \'post_status\' => \'inherit\'
                );
                $attach_id = wp_insert_attachment( $attachment, $file, $post_id );
                require_once(ABSPATH . \'wp-admin/includes/image.php\');
                $attach_data = wp_generate_attachment_metadata( $attach_id, $file );
                wp_update_attachment_metadata( $attach_id, $attach_data );

                set_post_thumbnail( $post_id, $attach_id );
                echo "Attachment ID: " . $attach_id;
                $post_thumbnail_id = get_post_thumbnail_id( $post_id );             
                echo "Thumbnail ID: " . $post_thumbnail_id; 
                get_the_post_thumbnail($post_id, \'full\');