無法轉換類型'[String：Any]'的值？'到期望的參數類型'_？'

Question

P和R是泛型類型

open func route<P,R>(url:URL , param : P?) -> R?{ 
    guard let s = url.scheme ,let h = url.host else{ 
     #if DEBUG 
      print("url error") 
     #endif 
     return nil 
    } 

    let urlString = "\(s)://\(h)\(url.path)" 


    guard let t = self.urlTaskMap[urlString] as? RoyTaskClosure<P,R> else { 

     print("closure unmatched,url -> \(urlString)") 

     return nil 
    } 

    let returnValue = t(param) 

    return returnValue 
} 

當我調用該函數像

public func viewController(url:URL,param:[String:Any]?) -> RoyProtocol?{ 
    if let vc = self.route(url: url, param: param){ 
     return vc 
    } 
    return nil 
} 

Xcode的告訴我一個錯誤信息

Cannot convert value of type '[String:Any]?' to expected argument type '_?' 

神！有人可以告訴我如何解決它？

Answer 1

我得到了solution.Replace你的方法與此

public func viewController(url:URL,param:[String:Any]?) -> RoyProtocol?{ 
    let vc: RoyProtocol? = self.route(url: url, param: param) 
    return vc 
}