facebook integration Error 2500 OAuthException xcode 8 Swift 3 - swift3

Question

I am working on facebook integration in xcode 8 Swift 3.
i have used the following code
let parameters = ["fields": "email, first_name, last_name, picture.type(large)"]
FBSDKGraphRequest.init(graphPath: "me", parameters: parameters).start { (connection, result, error) in
if error != nil{
print(error)
return
}
But I am getting below error.
Optional(Error Domain=com.facebook.sdk.core Code=8 "(null)" UserInfo={com.facebook.sdk:FBSDKGraphRequestErrorCategoryKey=0, com.facebook.sdk:FBSDKGraphRequestErrorHTTPStatusCodeKey=400, com.facebook.sdk:FBSDKErrorDeveloperMessageKey=An active access token must be used to query information about the current user., com.facebook.sdk:FBSDKGraphRequestErrorGraphErrorCode=2500, com.facebook.sdk:FBSDKGraphRequestErrorParsedJSONResponseKey={
body = {
error = {
code = 2500;
"fbtrace_id" = "FmK/8QACfhe";
message = "An active access token must be used to query information about the current user.";
type = OAuthException;
};
};
code = 400;
}})
can anyone help me out this ??

Answer 1

func loginButton(_ loginButton: FBSDKLoginButton!, didCompleteWith result: FBSDKLoginManagerLoginResult!, error: Error!) {
print("Login buttoon clicked")
let graphRequest:FBSDKGraphRequest = FBSDKGraphRequest(graphPath: "me", parameters: ["fields":"first_name, gender, last_name, email, picture.type(large)"])
graphRequest.start(completionHandler: { (connection, result, error) -> Void in
if ((error) != nil)
{
print("Error: \(error)")
}
else
{
let data:[String:AnyObject] = result as! [String : AnyObject]
print(data["first_name"]!)
print(data["last_name"]!)
print(data["email"]!)
print(data["id"]!)
print(data["gender"]!)
}
})
}