Trying to use NSNotification in a multipeer connectivity test app in Swift

Question

have been following this tutorial :

http://www.appcoda.com/intro-multipeer-connectivity-framework-ios-programming/

But have been converting it to work in Swift. Have come unstuck on the following however :

-(void)peerDidChangeStateWithNotification:(NSNotification *)notification
    {
        MCPeerID *peerID = [[notification userInfo] objectForKey:@"peerID"];
        NSString *peerDisplayName = peerID.displayName;
        MCSessionState state = [[[notification userInfo] objectForKey:@"state"] intValue];

It is the last line that is causing trouble, I have got this far :

func peerDidChangeStateWithNotification(notification: NSNotification)
{
    if let userInfo : AnyObject = notification.userInfo? {
        let peerID = userInfo["peerID"] as MCPeerID
        let state = userInfo["state"] as MCSessionState

But cannot get the "state" entry into type MCSessionState, getting the error :

'AnyObject' is not convertible to 'MCSessionState'

Can anyone help ... ? Quite new to Swift so sorry if this is an obvious one ...

Many thanks, Franco.

---

update 9sep :

the code that sets up the userInfo object in the first place is as follows, as far as I know calling the toRaw() method should just mean it treats it as if it were storing an Int ... ? In which case I don't know why your original answer doesn't work ...

func session(session: MCSession!, peer peerID: MCPeerID!, didChangeState state: MCSessionState)
{

    var dict = ["peerID": peerID, "state": state.toRaw()]

    NSNotificationCenter.defaultCenter().postNotificationName("MCDidChangeStateNotification", object: nil, userInfo: dict)

}

---

update 2 9sep :

Got it ! The full working version of the converted function is as follows if anyone else is following that same tutorial. Many thanks for your help Edwin Vermeer :

func peerDidChangeStateWithNotification(notification: NSNotification)
{
    if let userInfo : AnyObject = notification.userInfo?
    {
        let peerID = userInfo["peerID"] as MCPeerID
        let peerDisplayName = peerID.displayName
        let state: MCSessionState = MCSessionState.fromRaw(Int(userInfo["state"] as NSNumber)) as MCSessionState!

        if (state != MCSessionState.Connecting)
        {
            if (state == MCSessionState.Connected)
            {
                arrayConnectedDevices.append(peerDisplayName)
            }
            else if (state == MCSessionState.NotConnected)
            {
                if (arrayConnectedDevices.count > 0)
                {
                    if let i = find(arrayConnectedDevices, peerDisplayName)
                    {
                        arrayConnectedDevices.removeAtIndex(i)
                    }
                }
            }
        }
    }
}

Answer 1

You can use this to convert the int to the enum:

let state: MCSessionState = MCSessionState.fromRaw(Int(userInfo["state"] as NSNumber)) as MCSessionState!