     }
     
 }
+
+enum PanMoveDirection {
+    case PanMoveUp, PanMoveDown, PanMoveLeft, PanMoveRight, PanNone
+}

        }
    }
    
    /// 进行滑动手势时触发的方法
    /// - parameter recognizer: 滑动手势
    func pan(recognizer: UIPanGestureRecognizer) {
        switch recognizer.state {
        case .Began:
            // 记录上次滑动完成后父视图（DTCardView）的x坐标位置

    let maxCardTransformScalar: CGFloat = 0.65
    /// 处于视图中间的卡片
    var centerCard: DTCard?
    /// 计算滑动方向时的最小有效滑动量（x坐标或y坐标）
    var minimumPanTranslation: CGFloat = 15
    
    override init(frame: CGRect) {
        super.init(frame: frame)
