diff --git a/Sources/TabPageOption.swift b/Sources/TabPageOption.swift
index 61663d2..a821420 100644
--- a/Sources/TabPageOption.swift
+++ b/Sources/TabPageOption.swift
@@ -23,10 +23,11 @@ public struct TabPageOption {
     public var pageBackgoundColor: UIColor = UIColor.white
     public var isTranslucent: Bool = true
     public var hidesTabBarOnSwipe: Bool = false
-
-    internal var tabBarAlpha: CGFloat {
-        return isTranslucent ? 0.95 : 1.0
-    }
+    public var coverNavBar: Bool = false
+    public var tabBarAlpha: CGFloat = 0.95
+//    public var tabBarAlpha: CGFloat {
+//        return isTranslucent ? 0.95 : 1.0
+//    }
     internal var tabBackgroundImage: UIImage {
         return convertImage()
     }
diff --git a/Sources/TabPageViewController.swift b/Sources/TabPageViewController.swift
index 8d7ca25..f5b4ec3 100644
--- a/Sources/TabPageViewController.swift
+++ b/Sources/TabPageViewController.swift
@@ -25,9 +25,8 @@ open class TabPageViewController: UIPageViewController {
     }
     fileprivate var beforeIndex: Int = 0
     fileprivate var tabItemsCount = 0
-    fileprivate var defaultContentOffsetX: CGFloat {
-        return self.view.bounds.width
-    }
+    fileprivate var defaultContentOffsetX: CGFloat = UIScreen.main.bounds.width
+    
     fileprivate var shouldScrollCurrentBar: Bool = true
     lazy fileprivate var tabView: TabView = self.configuredTabView()
     fileprivate var statusView: UIView?
@@ -44,7 +43,7 @@ open class TabPageViewController: UIPageViewController {
 
         setupPageViewController()
         setupScrollView()
-        updateNavigationBar()
+        if option.coverNavBar { updateNavigationBar() }
     }
 
     override open func viewWillAppear(_ animated: Bool) {
@@ -62,7 +61,7 @@ open class TabPageViewController: UIPageViewController {
     override open func viewDidAppear(_ animated: Bool) {
         super.viewDidAppear(animated)
 
-        updateNavigationBar()
+        if option.coverNavBar { updateNavigationBar() }
         tabView.layouted = true
     }
 
@@ -72,6 +71,11 @@ open class TabPageViewController: UIPageViewController {
         navigationController?.navigationBar.shadowImage = nil
         navigationController?.navigationBar.setBackgroundImage(nil, for: .default)
     }
+    
+    
+    public func refreshTabs() {
+        tabView = configuredTabView()
+    }
 }