Cannot convert value of type 'NSURL?' to expected argument type 'URL'

问题

The error message I get from this code segment is "cannot convert value of type 'NSURL?' to expected argument type 'URL'". When I go onto my web browser, I can see the pdf file so I know it is working. The pdf files are stored a remote server. Please help!

override func viewDidLoad() {
    print("dir2: \(dir2) dir1: \(dir1)")
    let targetURL = NSURL(string: "http://example.com/\(dir1)/\(dir2).pdf")
    let request = NSURLRequest(URL: targetURL) //this is the line with error.
    webView.loadRequest(request)
}

回答1:

For these lines:

    let targetURL = NSURL(string: "http://example.com/\(dir1)/\(dir2).pdf")
    let request = NSURLRequest(URL: targetURL) 

Replace the NSURL with URL and NSURequest with URLRequest.

Your code should be:

    let targetURL = URL(string: "http://example.com/\(dir1)/\(dir2).pdf")
    let request = URLRequest(url: targetURL!) 

来源：https://stackoverflow.com/questions/39549928/cannot-convert-value-of-type-nsurl-to-expected-argument-type-url