Unable to call AppDelegate openURL( ) while using the Dropbox SDK

I'm trying to add Dropbox authentication to my app, but it's showing me this error:

DropboxSDK: app delegate does not implement application:openURL:sourceApplication:annotation:

Below is the code in my app delegate:

let dbSession = DBSession(appKey: dbAppKey, appSecret: dbAppSecret, root: kDBRootDropbox)
DBSession.setSharedSession(dbSession)

func application(app: UIApplication, openURL url: NSURL, options: [String : AnyObject]) -> Bool {

    if DBChooser.defaultChooser().handleOpenURL(url){
        return true
    }
    else if DBSession.sharedSession().handleOpenURL(url){

        if DBSession.sharedSession().isLinked(){
            return true
        }
    }
    return false
}

I had created an NSObject for authentication and handling other operations related to Dropbox API. Below is my authentication code:

if !DBSession.sharedSession().isLinked(){
    DBSession.sharedSession().linkFromController(viewController)
}
else{
    delegate.authenticationStatus!(true, error: nil)
}

I'm getting this error after it's successfully logged in. I had also set LSApplicationQueriesSchemes in my plist and also added the URL types. I'm unable to find where I'm making a mistake.

Also I'm trying to check if Dropbox app is present or not using

if UIApplication.sharedApplication().canOpenURL(NSURL(string: "dbapi-1://")!){
}

But it's giving me below error:

canOpenURL: failed for URL: "dbapi-1://" - error: "(null)"
canOpenURL: failed for URL: "dbapi-2://1/connect" - error: "(null)"

Any help will be appreciated.

Thanks in advance.

Your app delegate appears to implement a different openURL signature than what the SDK expects.

Change the signature to this instead:

func application(application: UIApplication, openURL url: NSURL,
    sourceApplication: String?, annotation: AnyObject) -> Bool {

Do take note that this method has been marked deprecated in the iOS 9 SDK. It will continue to work as expected for a while though.