回複：太感謝了！可是我違例在先（2004年），

When you get a new visa to come back form outside of U.S., all your previous unlawful prsence will be automatically removed and it will not affect your I-485 anymore. I do not think you have a problem to get the H4 visa in Canada because USCIS have not realized your violation of status ye (they usually only check this when they make a decision on your I-485).