import UIKit
 
class ViewController: UIViewController {
 
    var activityIndicator:UIActivityIndicatorView!
     
    override func viewDidLoad() {
        super.viewDidLoad()
         
        activityIndicator = UIActivityIndicatorView(activityIndicatorStyle:
            UIActivityIndicatorViewStyle.Gray)
        activityIndicator.center=self.view.center
        self.view.addSubview(activityIndicator);
         
        play()
    }
     
    func play(){
        //进度条开始转动
        activityIndicator.startAnimating()
    }
     
    func stop(){
        //进度条停止转动
        activityIndicator.stopAnimating()
    }

}

• 设置本界面不可点击，但是导航栏除外

self.view.isUserInteractionEnabled = false