swift - Try Catch in Swift, Can't figure it out

Question

I'm trying to put the following in a do try catch block, but I always end up getting a coding error. Can someone help me?

 let here = CGRect(x: UIScreen.main.bounds.width - 30, y: 80, width: 10, height: 10)
        DispatchQueue.main.asyncAfter(deadline: .now() + 2) {
            let popTip = PopTip()
            popTip.show(text: "Font Sizes", direction: .down, maxWidth: 200, in: (self.navigationController?.view)! , from: here, duration: 3)
        }

Answer 1

您的问题是您没有任何实际引发错误的内容（即标有try）。我无法完全理解您在评论中所说的内容，但是我相信您可以在没有do-catch子句的情况下解决此问题，但可以使用guard-let检查 if self.navigationController.viewis的语句nil。如果是nil，只是return功能。