我有这个方法在Swift 2.2中工作,但自从我将代码转换为Swift 3后,它不再有效,此方法所做的就是取用户名和密码登录到Windows身份验证的URL中,如果信誉正确,则返回true,如果它们不正确,则返回false。致命错误:意外地发现零,同时解开URLSession的可选值
这里是方法:
func loginUser(_ username: String, password: String, completion: @escaping (_ result: Bool) -> Void)
{
//Setup the NSURLSessionConfiguration
let configuration = URLSessionConfiguration.default
//Setup the NSURLSession
let session = Foundation.URLSession(configuration: configuration, delegate: self, delegateQueue: nil)
//Add the username and password to NSURLCredential
credential = URLCredential(user:username, password:password, persistence: .forSession)
//Create request URL as String
let requestString = NSString(format:"%@", webservice) as String
//Convert URL string to NSURL
let url: URL! = URL(string: requestString)
//Prepare the task to get data.
let task = session.dataTask(with: url, completionHandler: {
data, response, error in
DispatchQueue.main.async(execute: {
if(error == nil)
{
//If there is no error calling the API, return true
completion(true)
}
else
{
//If there is an error calling the API, return false
completion(false)
}
})
})
//Run the task to get data.
task.resume()
}
,我得到这个错误:
fatal error: unexpectedly found nil while unwrapping an Optional value
这种情况发生时就在这里:
let task = session.dataTask(with: url, completionHandler: {
data, response, error in
DispatchQueue.main.async(execute: {
if(error == nil)
{
//If there is no error calling the API, return true
completion(true)
}
else
{
//If there is an error calling the API, return false
completion(false)
}
})
})
我在做什么错?
这出现在我的调试导航器中的致命错误之前:
function signature specialization <preserving fragile attribute, Arg[1] = [Closure Propagated : reabstraction thunk helper from @callee_owned (@unowned Swift.UnsafeBufferPointer<Swift.UInt8>) ->() to @callee_owned (@unowned Swift.UnsafeBufferPointer<Swift.UInt8>) -> (@out()), Argument Types : [@callee_owned (@unowned Swift.UnsafeBufferPointer<Swift.UInt8>) ->()]> of generic specialization <preserving fragile attribute,()> of Swift.StaticString.withUTF8Buffer <A> ((Swift.UnsafeBufferPointer<Swift.UInt8>) -> A) -> A
我相信我的问题是在这里:
/**
Requests credentials from the delegate in response to a session-level authentication request from the remote server.
*/
func urlSession(_ session: URLSession, didReceive challenge: URLAuthenticationChallenge, completionHandler: @escaping (URLSession.AuthChallengeDisposition, URLCredential?) -> Void) {
if challenge.previousFailureCount > 0
{
completionHandler(Foundation.URLSession.AuthChallengeDisposition.cancelAuthenticationChallenge, nil)
}
else
{
completionHandler(Foundation.URLSession.AuthChallengeDisposition.useCredential, URLCredential(trust:challenge.protectionSpace.serverTrust!))
}
}
/**
Requests credentials from the delegate in response to an authentication request from the remote server.
*/
func urlSession(_ session: URLSession, task: URLSessionTask, didReceive challenge: URLAuthenticationChallenge, completionHandler: @escaping (URLSession.AuthChallengeDisposition, URLCredential?) -> Void) {
completionHandler(Foundation.URLSession.AuthChallengeDisposition.useCredential,credential)
}
它不喜欢这些方法。
例如,如果它的工作,我会接受你的答案。 – user979331
'url'可能是零。 'requestString'的价值是什么? – dan
url与requestString不是零,它不是零 – user979331