swift - 快速更新表格 View 单元格

Question

背景

我有一个简单的账单拆分应用程序，允许用户将餐点分配给多个人或用户。当餐点分给多人时，价格相应平分。膳食(包含项目名称和价格是行，用户是部分。

当我删除一行时，我想删除该行，并更新或更改某些其他值(我基本上想在用户删除某项时将价格重新分配给少一个人)。我的数据模型是一个多维 数组。在这里:

 struct UserModel {
    var name: String
    var itemModels = [ItemModel]()

    init(name: String, itemModels: [ItemModel]? = nil) {
        self.name = name
        if let itemModels = itemModels {
            self.itemModels = itemModels
        }
    }
}

    struct ItemModel {
    var itemName: String
    var price: Double

    init(itemName: String, price: Double) {
        self.itemName = itemName
        self.price = price
    }
}
    class Data {
    static var userModels = [UserModel]()
    static var itemModels = [ItemModel]()
}

例如，在 trailingSwipeActionsConfigurationForRowAt

func tableView(_ tableView: UITableView, trailingSwipeActionsConfigurationForRowAt indexPath: IndexPath) -> UISwipeActionsConfiguration? {
    let delete = UIContextualAction(style: .destructive, title: "Delete") { (contextualAction, view, actionPerformed: @escaping (Bool) -> ()) in

        let user = Data.userModels[indexPath.section].name
        let item = Data.userModels[indexPath.section].itemModels[indexPath.row].itemName
        let price = Data.userModels[indexPath.section].itemModels[indexPath.row].price


        ItemModelFunctions.removeFromUser(from: indexPath.section, remove: indexPath.row)

        var duplicate = Data.userModels.filter({$0.itemModels.contains(where: {$0.itemName == item})}).filter({$0.name != user}) 

        for i in 0..<duplicate.count {
            ???
        }
        tableView.reloadData()
        actionPerformed(true)
    }
    return UISwipeActionsConfiguration(actions: [delete])
}

变量 var duplicate 返回在 indexPath.row 有相同项目的其他用户的数组，但不是用户(indexPath.section ) 谁拥有该元素。我知道这听起来很困惑，但如果需要，我可以提供更多代码或 print 语句。

同样在for循环中，我想做这样的事情:

for i in 0..<duplicate.count {
    let oldPrice = duplicate[i].price
    let newPrice = oldPrice * duplicate.count
    duplicate[i].price = newPrice
}

但我无法访问价格。我认为需要 indexPath.section 和 indexPath.row。

如果您做到了这一点，感谢您抽出宝贵时间。我觉得我需要一个嵌套循环，但我不确定具体如何实现它。如果有任何其他更简单的方法来实现这一点，我愿意接受任何建议。

非常感谢!

编辑: 标记的答案有效!如果其他人遇到类似问题，这就是我在 trailingSwipeActionsConfigurationForRowAt 中的最终代码:

func tableView(_ tableView: UITableView, trailingSwipeActionsConfigurationForRowAt indexPath: IndexPath) -> UISwipeActionsConfiguration? {
    let delete = UIContextualAction(style: .destructive, title: "Delete") { (contextualAction, view, actionPerformed: @escaping (Bool) -> ()) in

        let item = Data.userModels[indexPath.section].itemModels[indexPath.row]
        ItemModelFunctions.removeFromUser(from: indexPath.section, remove: indexPath.row)

        let duplicate = Data.userModels.filter({$0.itemModels.contains(item)})

        for i in 0..<Data.userModels.count {
            if let idx = Data.userModels[i].itemModels.firstIndex(of: item) {
                let oldPrice = Data.userModels[i].itemModels[idx].price

                let newPrice = oldPrice * Double(duplicate.count+1)

                Data.userModels[i].itemModels[idx].price = newPrice / Double(duplicate.count)
            }
        }
        tableView.reloadData()
        actionPerformed(true)
    }
    return UISwipeActionsConfiguration(actions: [delete])
}

Answer 1

也许你可以试试这个。祝你好运，如果它不起作用，请发表评论。我是 Swift 的新手 :)

let actualItem = Data.userModels[indexPath.section].itemModels[indexPath.row]

for i in 0..<duplicate.count {
  if let idx = duplicate[i].itemModels.firstIndex(of: actualItem) {
     let oldPrice = duplicate[i].itemModels[idx].price
     duplicate[i].itemModels[idx].price = oldPrice * duplicate.count
  }
}