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I have been searching for quite a while for a solution as to how to grant users the ability to underline, italicize and bold text in a UITextView but have not been able to find a solid solution. I have realized that I will need to use an NSAttributedString but am not sure as to how to create the UI and format the string so I am able to save it to a database. If you could point me in a proper direction that would be greatly appreciated. Thanks!
The UI is simply an ordinary editable UITextView with allowsEditingTextAttributes set to true.
How you save is up to you, but the most universal solution is probably to pull out the UITextView's attributedText, archive it into an NSData (now known as Data in Swift), and save it off.
来源：https://stackoverflow.com/questions/41798358/how-to-add-underline-bold-italicize-abilities-for-uitextview-swift