是的，这是可能的。您只需使用regex解析HTML来获取图像URL，将其上载到uploads文件夹，然后将其设置为特色图像。

像这样：

function set_featured_image_from_html( $html, $post_id ) {
    // If there are no images in the HTML, return early.
    if ( ! preg_match( \'/<img\\s+.*?src=[\\"\\\']?([^\\"\\\' >]*)[\\"\\\']?[^>]*>/i\', $html, $image ) ) {
        return;
    }

    $image_url = $image[1];

    $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 );
}

set_featured_image_from_html(\'<img src="https://picsum.photos/800">\', 29);