         collectionView!.alwaysBounceVertical = true
         
         setTabNavigationTitle(["title": _photoAssetCollection.localizedTitle ?? "", "range": 0..<2])
-        let cancel = TabNavigationItem(title: "取消", target: self, selector: #selector(_handleCancelAction(_:)))
-        setTabNavigationItems([cancel])
         // Register asset collection cell.
         collectionView!.register(_AssetCollectionCell.self, forCellWithReuseIdentifier: String(describing: _AssetCollectionCell.self))
         
         collectionView!.contentInset = UIEdgeInsets(top: tabNavigationController!.tabNavigationBar.bounds.height, left: 0.0, bottom: 0.0, right: 0.0)
         collectionView!.scrollIndicatorInsets = collectionView!.contentInset
         collectionView!.allowsMultipleSelection = true
-    }
-}
-
-// MARK: Actions.
-
-extension _AssetCollectionViewController {
-    @objc
-    fileprivate func _handleCancelAction(_ sender: UIButton) {
-        self.tabNavigationController!.dismiss(animated: true, completion: nil)
     }
 }
 

        // Do any additional setup after loading the view.
        view.backgroundColor = UIColor(colorLiteralRed: 0.976, green: 0.976, blue: 0.976, alpha: 1.0)
        tabNavigationBar.isTranslucent = true
    }

    override func didReceiveMemoryWarning() {

        let option = PHFetchOptions()
        option.includeHiddenAssets = true
        option.includeAllBurstAssets = false
        return PHAssetCollection.fetchAssetCollections(with: .smartAlbum, subtype: .any, options: option)
    }
    
