模拟按Home键退出应用的简单方法(分享)

func exitApplication() { 
    let app = UIApplication.sharedApplication().delegate as! AppDelegate
    let window = app.window
    dispatch_async(dispatch_get_main_queue(), { 
      UIView.animateWithDuration(0.5, animations: { 
        window!.alpha = 0
        window?.frame = CGRectMake((window?.bounds.size.width)!/2.0, (window?.bounds.size.height)!/2.0, 0, 0) 
      }) { (finish) in
        exit(0) 
      } 
    }) 
  }