Outlook has an email encryption function. Emails with this feature turned on will not be able to be screenshotted. When the recipient takes a screenshot of this email, the screenshot result is a black screen.
I searched for ways to take screenshots on Windows, and the bitBlt function was called. There is nothing special about this function. I want to know how Outlook controls the screenshot software to be unable to take screenshots, because it cannot decide how other software calls this function, nor can it modify the calling parameters. How the code is implemented?
Thank you for taking the time to answer my questions and satisfy my curiosity. :)
I'm a Java programmer and can read basic c++ code, describing the logic in pseudo-code is fine.