如何在swiftui中实现分组列表上的move

Question

如何在分组列表中实现onMove函数？不幸的是，我看不到从哪里获得"公司"信息。。。

这是代码：

import SwiftUI

struct Person: Identifiable, Hashable {
var id = UUID()
var name: String
}
struct Company : Identifiable, Hashable {
var id = UUID()
var name: String
var employees : [Person]
}
class CompanyList: ObservableObject {
@Published var companies = [
Company(name: "Apple", employees: [Person(name:"Bob"), Person(name:"Brenda")]),
Company(name: "Microsoft", employees: [Person(name:"Bill"), Person(name:"Lucas")]),
Company(name: "Facebook", employees: [Person(name:"Mark"), Person(name:"Sandy")])
]
func deleteListItem(whichElement: IndexSet, from company: Company) {
let index = companies.firstIndex(of: company)!
companies[index].employees.remove(atOffsets: whichElement)
}
func moveListItem(whichElement: IndexSet, to companyIndex: Int) {
print(whichElement.first)
if whichElement.count > 1 {
whichElement.dropFirst()
print(whichElement.first)
}
print(companyIndex)
//        let employee = companies[index].employees[whichElement.first!]
//        companies[index].employees.remove(at: whichElement.first!)
//
}
}
struct  ContentView: View {
@ObservedObject var companyList = CompanyList()
@State var text : String = ""
var body: some View {
NavigationView {
VStack {
List () {
ForEach (companyList.companies, id: .self) { company in
Section(header: Text(company.name)) {
ForEach(company.employees) { employee in
Text(employee.name).id(UUID())
}
.onDelete { (indexSet) in
self.companyList.deleteListItem(whichElement: indexSet, from: company)
}
.onMove { indexSet, intValue in
self.companyList.moveListItem(whichElement: indexSet, to: intValue)
}
.onInsert(of: ["chris"]) { (intValue, _) in
print("wtf")
}
}
}
}
.listStyle(GroupedListStyle())
.navigationBarItems(trailing: EditButton())
}
}
}
}

Answer 1

有两个主要更改和一个swiftUI缺陷。

1. 更新了方法moveListItem

2. 通过NavigationalLink 创建了一个替代方案来改变公司

3. SwiftUI没有在具有.onMove()的GroupedList中的组之间移动的选项

该应用程序在技术上是可行的。但除非苹果添加该功能，否则不会如你所愿。还有一个选项，那就是使用自定义移动方法创建自定义列表视图，这是完全不同的主题。

import SwiftUI
struct Person: Identifiable, Hashable {
var id = UUID()
var name: String
}
struct Company : Identifiable, Hashable {
var id = UUID()
var name: String
var employees : [Person]
}
class CompanyList: ObservableObject {
@Published var companies = [
Company(name: "Apple", employees: [Person(name:"Bob"), Person(name:"Brenda")]),
Company(name: "Microsoft", employees: [Person(name:"Bill"), Person(name:"Lucas")]),
Company(name: "Facebook", employees: [Person(name:"Mark"), Person(name:"Sandy")])
]
func deleteListItem(whichElement: IndexSet, from company: Company) {
if let index = self.companies.firstIndex(of: company) {
self.companies[index].employees.remove(atOffsets: whichElement)
}
}
func moveListItem(whichElement: IndexSet, to companyIndex: Int, from company: Company) {
if let index = self.companies.firstIndex(of: company) {
self.companies[index].employees.move(fromOffsets: whichElement, toOffset: companyIndex)
}
}
}

struct  TestView: View {
@EnvironmentObject var companyList: CompanyList
@State var text : String = ""
var body: some View {
NavigationView {
VStack {
List () {
ForEach (companyList.companies, id: .self) { company in
Section(header: Text(company.name)) {
ForEach(company.employees) { employee in
NavigationLink(destination: EditEmployee(company: company, employee: employee)){
Text(employee.name)
}.id(UUID())
}
.onDelete { (indexSet) in
self.companyList.deleteListItem(whichElement: indexSet, from: company)
}
.onMove { indexSet, intValue in
self.companyList.moveListItem(whichElement: indexSet, to: intValue, from: company)
}
.onInsert(of: ["chris"]) { (intValue, _) in
print("wtf")
}
}
}
}
.listStyle(GroupedListStyle())
.navigationBarItems(trailing: EditButton())
}
}
}
}

struct EditEmployee: View {
@EnvironmentObject var companyList: CompanyList
var company: Company
var employee: Person
var body: some View {
VStack(alignment: .leading) {
Text("Company")
Picker(selection: Binding<Company>(
get: { () -> Company in
return self.company
}, set: { (company) in
if let cid = self.companyList.companies.firstIndex(of: self.company) {
if let eid =  self.companyList.companies[cid].employees.firstIndex(of: self.employee) {
if let ncid = self.companyList.companies.firstIndex(of: company) {
self.companyList.companies[cid].employees.remove(at: eid)
self.companyList.companies[ncid].employees.append(self.employee)
}
}
}
}
), label: Text("")){
ForEach(self.companyList.companies) { company in
Text(company.name).tag(company)
}
}.pickerStyle(SegmentedPickerStyle())
Spacer()
}.padding()
.navigationBarTitle(self.employee.name)
}
}