Cant change Canvas Parametres

Hey everyone) May be comeone can help with this

Code (CSharp):

1.  
2. private void AddCanvasToObject(GameObject gmo) {
3. gmo.AddComponent<Canvas>();
4. Canvas _canvas = gmo.GetComponent<Canvas>();
5. _canvas.overrideSorting = true;
6. _canvas.sortingLayerName = sordinglayerName;
7. _canvas.sortingOrder = TutorialManager.TUTORIAL_ORDER;
8. TutorialManager.TUTORIAL_ORDER++;
9. }

Im trying added canvas to some ui element(Image Element) and change canvas parametres(overrife sorting layer and order), Canvas added succesfull, but parametres not changed))) what i deal wrong)