快速更新表视图单元格

Question

>背景

我有一个简单的账单拆分应用程序，允许用户将膳食项目分配给多个人或用户。当餐点分配给多个人时，价格将相应地分配。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(我基本上想在从用户中删除项目时将价格重新分配给少一个人)。我的数据模型是一个multidimensionalarray。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具有相同项目的其他用户的数组，但不返回拥有该项目的用户(indexPath.section)。我知道这听起来很令人困惑，但如果需要，我可以提供更多代码或print语句。

同样在for loop，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
}

但我无法获得价格。我相信需要一个indexPath.section和indexPath.row.

如果您做到了这一步，感谢您抽出宝贵时间。我觉得我需要一个嵌套循环，但我不确定如何准确实现它。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的问题，这就是我的最终代码在trailingSwipeActionsConfigurationForRowAt中的样子：

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
}
}