I keep having to look up how to change the same deprecated functions, so I thought I’d make myself a list here for quick reference.

Before	After
file_create_url($uri)	\Drupal::service('file_url_generator')->generateAbsoluteString($uri)
file_url_transform_relative($file_url)	\Drupal::service('file_url_generator')->transformRelative($file_url)
file_url_transform_relative( file_create_url($uri))	\Drupal::service('file_url_generator')->generateString($uri)
Drupal\Core\Url::fromUri( file_create_url($uri))	\Drupal::service('file_url_generator')->generate($uri)
render($render_array)	\Drupal::service(‘renderer’)->render($render_array)

Messages

Before	After
$messenger = \Drupal::messenger(); $messenger->deleteByType(‘error’);	\Drupal::service('messenger')->deleteByType('error');