google map sdk ios GMSPanoramaViewDelegate

想使用 google map sdk for ios 中的Panorama Delegate，但是在运行delegate 的各类function 的时候 没有任何反应，设置er 的info window 点击的时候也米有任何窗口 ,代码如下，求大神教啊！！
import Foundation
import UIKitclass panViewController: UIViewController,GMSPanoramaViewDelegate{
    let screenSize: CGRect = UIScreen.mainScreen().bounds
    var lat_map = 43.649615
    var lng_map = -79.39162
    var panoView : GMSPanoramaView?
    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
        panoView = GMSPanoramaView(frame: CGRectMake(0, 0, self.view.bounds.width, self.view.bounds.height))
        panoView!.moveNearCoordinate(CLLocationCoordinate2DMake(43.749615,lng_map))
        
        panoView!.delegate = self
        self.view.addSubview(panoView!)
        
        var position = CLLocationCoordinate2DMake(43.749615,lng_map)
        var er = GMSMarker(position: position)
        
        er.snippet = "addd"
        er.title = "a"
        er.panoramaView = panoView
        
    }
    
    func panoView(pano:GMSPanoramaView!, didTapMarker er:GMSMarker!){
        
        print("working")
    }
    
    func panoView(pano:GMSPanoramaView!, didTap point:CGPoint!){
        println("working")
    }
    
    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }
    
    
}