Under the Criminal Code of Canada:
"prohibited weapon" means
(a) a knife that has a blade that opens automatically by gravity or centrifugal force or by hand pressure applied to a button, spring or other device in or attached to the handle of the knife,
So, your knife it is opened with one hand, if by centrifugal force or gravity is prohibited to own or carry. A folding knife on its' own is not prohibited but since yours is opened in this fashion it is prohibited. If your knife needed both hands to open it would be completely legal to carry with you.
The length does not matter, you could carry a sword with you if you wanted but you would attract negative attention from the public and police. The issue becomes the PURPOSE you are carrying the weapon. There are rules about possession that might cause you some grief.
Get rid of that knife and get one that is not prohibited. Below is a link to the Criminal Code of Canada and if you read Part III, Possession Offences (88 and up) you will get a better idea of your rights and responsibilities.
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