I want to post answers to homework questions after my assignments close. I don't want the students to see the files or link to the files. Is this possible? How do I do it?
You can restrict access to students by date. Here's a guide with screenshots: How do I restrict files and folders to students in Canvas?
While that focuses on the files area, it'll also prevent them from opening/seeing it in other spots on canvas as well.
Anthony is correct with the information he provided, but in answer to the other part of your question, you can prevent the students from accessing/opening the file, you can't prevent them from "seeing" the file.
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