         collectionView.delegate = self
         collectionView.autoresizingMask = [.flexibleWidth, .flexibleHeight]
         collectionView.register(TTAAssetCollectionViewCell.self, forCellWithReuseIdentifier: "\(TTAAssetCollectionViewCell.self)")
+    }
+    
+    func _prepareCancelItem() {
+        if UIDevice.current.userInterfaceIdiom == .pad { return }
+        let cancelItem = UIBarButtonItem(barButtonSystemItem: .cancel, target: self, action: #selector(didClickCancelItem))
+        self.navigationItem.rightBarButtonItem = cancelItem
     }
     
     func _prepareIconFont() {

        _createViews()
        _configViews()
        _layoutViews()
        _startCaching()
    }
    

    }
}

// MARK: - Actions

extension TTAAssetPickerViewController {
    func didClickCancelItem() {
        dismiss(animated: true, completion: nil)
    }
}

// MARK: - UICollectionViewDataSource

extension TTAAssetPickerViewController: UICollectionViewDataSource {
