所以我有 FBViewController 类，它应该显示一个按钮让我登录和注销(只是为了测试 FB 登录)。我将其集成到新创建的项目中并且一切正常。然后我将其重新设计到我的应用程序中，但它无法正常工作。不确定它是否与 swift 版本或其他有关...... 使用 Xcode 10.0

import UIKit
import FBSDKLoginKit

class FBViewController: UIViewController, FBSDKLoginButtonDelegate {


    override func viewDidLoad() {
        super.viewDidLoad()
        let btnFBLogin = FBSDKLoginButton()
        btnFBLogin.readPermissions = ["public_profile", "email"]
        btnFBLogin.delegate = self
        btnFBLogin.center = self.view.center
        self.view.addSubview(btnFBLogin)

        if FBSDKAccessToken.current() != nil{
            print("Logged IN ALREADY")
            printInfo()
        }else{
            print("not logged in")
        }

    }

    func loginButton(_ loginButton: FBSDKLoginButton!, didCompleteWith result: FBSDKLoginManagerLoginResult!, error: Error!) {
        if error != nil{
            print(" error")
      //      print(error.localizedDescription)
        }else if result.isCancelled {
            print("User cancelled.")
        }
        else {
            print("Logge IN!")
            printInfo()
        }
    }

    func loginButtonDidLogOut(_ loginButton: FBSDKLoginButton!) {
        print("logged out")
    }

    func printInfo(){


        if(FBSDKAccessToken.current() != nil){

            FBSDKGraphRequest(graphPath: "me", parameters: ["fields": "id,name , first_name, last_name , email"]).start(completionHandler: { (connection, result, error) in

                guard let Info = result as? [String: Any] else { return }

                if let userName = Info["name"] as? String
                {
                    print(userName)
                }

            })
        }
    }

}

FBSDKLoginButtonDelegate

/**
 @protocol
  A delegate for `FBSDKLoginButton`
 */
@protocol FBSDKLoginButtonDelegate <NSObject>

@required
/**
  Sent to the delegate when the button was used to login.
 @param loginButton the sender
 @param result The results of the login
 @param error The error (if any) from the login
 */
- (void)loginButton:(FBSDKLoginButton *)loginButton
didCompleteWithResult:(FBSDKLoginManagerLoginResult *)result
                error:(NSError *)error;

/**
  Sent to the delegate when the button was used to logout.
 @param loginButton The button that was clicked.
*/
- (void)loginButtonDidLogOut:(FBSDKLoginButton *)loginButton;

@optional
/**
  Sent to the delegate when the button is about to login.
 @param loginButton the sender
 @return YES if the login should be allowed to proceed, NO otherwise
 */
- (BOOL) loginButtonWillLogin:(FBSDKLoginButton *)loginButton;

@end

添加协议(protocol) stub 只会添加 1 个函数(loginButton...)，该函数已实现，但似乎无法识别它。

我尝试清理项目、删除派生数据、重新启动，但它仍然给我同样的错误:

Type 'FBViewController' does not conform to protocol 'FBSDKLoginButtonDelegate'

感谢帮助! 谢谢

最佳答案

经过大量搜索，我找到了这个问题的答案，描述为 here

我导入了 Turbolinks-ios，它有自己的错误结构，我不得不在方法 stub 中使用 Swift.Error -

 func loginButton(_ loginButton: FBSDKLoginButton!, didCompleteWith result: FBSDKLoginManagerLoginResult!, error: Swift.Error!) {...

关于swift - 符合协议(protocol)——一次又一次地添加协议(protocol) stub 并不能修复错误，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/53156908/