Hi,   How do I check to see if a Character is in a Character Set?   In Objective-C, I could write:   [[NSCharacterSet lowercaseLetterCharacterSet] characterIsMember:c]   Where “c” is a variable of type char.   In Swift, I tried to write:   CharacterSet.lowercaseLetters.contains(c)  …

I am making an app to display magazines as PDFs. Sometimes whilst viewing the PDF (usually after scrolling and zooming around), certain pages will turn black. I have linked a screenshot of this problem.   The black pages return to normal after I reload the…

I`m trying to make my own OpenVPN client using NetworkExtension. I’m following these instructions:   https://github.com/ss-abramchuk/OpenVPNAdapter   But I cant get it to work. I create my manager succesfully, without any errors. But then when I call startTunnel() nothing happens. No error (I have my…