需要实现这样如下效果：

image.png

主要方法如下：

func SetMutiBorderRoundingCorners(_ rectCorner: UIRectCorner, corner: CGFloat) {
        
        //        [UIRectCorner.bottomLeft, UIRectCorner.topRight]
        
        let maskPath = UIBezierPath.init(roundedRect: self.bounds,
                                         
                                         byRoundingCorners: rectCorner,
                                         
                                         cornerRadii: CGSize(width: corner, height: corner))
        
        let maskLayer = CAShapeLayer()
        
        maskLayer.frame = self.bounds
        
        maskLayer.path = maskPath.cgPath
        
        self.layer.mask = maskLayer
        
    }
    

定义一个枚举

enum RedMyPageCellUIPostion {
    case top         // 顶部
    case center      // 中间
    case bottom      // 底部
}

根据枚举值来设置cell的圆角

var cellPosition :RedMyPageCellUIPostion = .center {
        didSet {
            switch cellPosition {
            case .top:
                self.bgView.SetMutiBorderRoundingCorners([.topLeft, .topRight], corner: 10.0)
            case .center:
                self.bgView.SetMutiBorderRoundingCorners([.allCorners], corner: 0.0)
            case .bottom:
                self.bgView.SetMutiBorderRoundingCorners([.bottomLeft, .bottomRight], corner: 10.0)
            }
        }
    }
    

在列表数据源处，根据数据源设置cell的枚举值

var memuList :[[Model]] = [[Model]]()
......
func numberOfSections(in tableView: UITableView) -> Int {
        return self.memuList.count;
    }
   
    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        let groupMenus = self.memuList[section];
        return groupMenus.count
    }
    
......
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = self.tableView.dequeueReusableCell(withIdentifier: kCellID, for: indexPath) as! MyCell
        
        cell.accessoryType = .disclosureIndicator
        cell.selectionStyle = .none
        let groupMenus = self.memuList[indexPath.section];
        if 0 == indexPath.row {
            cell.cellPosition = .top
        } else if indexPath.row == (groupMenus.count - 1) {
            cell.cellPosition = .bottom
        } else {
            cell.cellPosition = .center
        }
            
        let model = groupMenus[indexPath.row]

        ......

        return cell
    }

以上