         let offsetY = scrollView.contentOffset.y
         
         // 导航栏渐变
-        navigationController?.navigationBar.alpha = offsetY / 200
+        navigationController?.navigationBar.alpha = offsetY / 100
         
         // 下拉放大头部视图
         if offsetY < 0 {

        return headerView
    }()
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        let rightButton = UIButton(type: UIButtonType.Custom)
        rightButton.setTitle("设置", forState: UIControlState.Normal)
        rightButton.sizeToFit()
        rightButton.titleLabel?.font = UIFont.systemFontOfSize(15)

        
    }
    
    override func viewWillAppear(animated: Bool) {
        super.viewWillAppear(animated)
        rightButton.hidden = false
    }
    
    override func viewWillDisappear(animated: Bool) {
        super.viewWillDisappear(animated)
        rightButton.hidden = true
    }
    
    override func tableView(tableView: UITableView, heightForHeaderInSection section: Int) -> CGFloat {
        return 0.1
    }
