我正在运行一个函数，以填充费用清单。我需要运行功能以使用.onAppear(perform: fetchRows)填充列表，以便列表在视图显示后立即更新。
每个列表项也是一个按钮。单击后将显示带有费用信息的工作表。如果需要，可以对其进行编辑。我需要的是此表更新Expense Core Data Entity实体。
工作表需要一个Expenses对象，但是我的列表由ExpensesList数组填充。如何从我的ExpensesList数组中为表单提供Expenses对象？如果有帮助的话，我在ExpensesList数组中有Expenses对象的ID。
import SwiftUI
import CoreData
@available(iOS 14.0, *)
struct ExpenseList: View {
@State var editExpense: Expenses?
@State var addExpense = false
@Environment(\.managedObjectContext)
var context: NSManagedObjectContext
@FetchRequest(fetchRequest: Expenses.expensesList)
private var result: FetchedResults<Expenses>
@State var expensesList: [ExpensesList]?
init(predicate: NSPredicate?, sortDescriptor: NSSortDescriptor) {
let fetchRequest = NSFetchRequest<Expenses>(entityName: Expenses.entity().name ?? "Expenses")
fetchRequest.sortDescriptors = [sortDescriptor]
if let predicate = predicate {
fetchRequest.predicate = predicate
}
_result = FetchRequest(fetchRequest: fetchRequest)
}
var body: some View {
NavigationView{
VStack{
if expensesList != nil{
List{
ForEach(self.expensesList!) { log in
Button(action: {
self.editExpense = log <--- Cannot assign value of type 'ExpensesList' to type 'Expenses'
}) {
ExpenseRow(name: log.expense, date: log.date, amount: log.cost, account: log.account)
}
}.onDelete(perform: onDelete)
}
}
}.navigationTitle("Expense List")
.navigationBarItems(trailing:
Button(action: {
self.addExpense.toggle()
}, label: {
Image(systemName: "plus.circle.fill")
}))
.sheet(item: $editExpense, onDismiss: {
self.editExpense = nil
})
{
(log: Expenses) in
ExpenseDetail(
context: self.context,
editExpense: log,
name: log.expenseName ?? "",
amount: String(log.expenseCost),
category: log.expenseCategory ?? "",
date: log.expenseDate ?? Date(),
account: log.expenseAccount ?? "",
isMonthly: log.expenseIsMonthly
).environment(\.managedObjectContext, self.context)
}
}.onAppear(perform: fetchRows)
.background(EmptyView()
.sheet(isPresented: $addExpense, content: {
ExpenseDetail(context: context)
}))
}
func fetchRows(){
Expenses.fetchAllExpensesInDateRange(context: self.context) { (results) in
guard !results.isEmpty else { return }
self.expensesList = results.map({ (result) -> ExpensesList in
print(result.id,result.expenseName,result.expenseCost, result.expenseAccount, result.expenseDate)
return ExpensesList(id: result.id, expense: result.expenseName, cost: result.expenseCost, account: result.expenseAccount, date: result.expenseDate)
})
}
}
private func onDelete(with indexSet: IndexSet) {
indexSet.forEach { index in
let log = result[index]
context.delete(log)
}
try? context.saveContext()
}
}
struct ExpensesList: Identifiable, Equatable {
let id: UUID
let expense: String
let cost: Double
let account: String
let date: Date
}
extension View {
func Print(_ vars: Any...) -> some View {
for v in vars { print(v) }
return EmptyView()
}
}