【发布时间】：2021-12-24 15:28:04
【问题描述】：
我有一个场景，我知道我需要做什么，但不知道如何在 Swift 中实现它......
我在 CoreData 中有 2 个表，我获取它们的值如下
我需要什么 - 特定用户好友数组中的所有好友
//-----完整代码 手动 CachedUser 类
import Foundation
import CoreData
extension CachedUser {
@nonobjc public class func fetchRequest() -> NSFetchRequest<CachedUser> {
return NSFetchRequest<CachedUser>(entityName: "CachedUser")
}
@NSManaged public var name: String?
@NSManaged public var id: String?
@NSManaged public var company: String?
@NSManaged public var isActive: Bool
@NSManaged public var age: Int16
@NSManaged public var email: String?
@NSManaged public var address: String?
@NSManaged public var about: String?
@NSManaged public var registered: String?
@NSManaged public var tags: String?
@NSManaged public var friends: NSSet?
public var wrappedName: String {
name ?? "Name N/A"
}
public var wrappedId: String {
id ?? "id N/A"
}
public var wrappedCompany: String {
company ?? "comapny N/A"
}
public var wrappedIsActive: Bool {
isActive
}
public var checkIsActive: String {
return isActive ? "YES" :"NO"
}
public var wrappedEmail: String {
email ?? "email N/A"
}
public var wrappedAge: Int16 {
age
}
public var wrappedRegistered: String {
registered ?? "N/A"
}
public var cachedFriend: [CachedFriend] {
let set = friends as? Set<CachedFriend> ?? []
return set.sorted {
$0.wrappedName < $1.wrappedName
}
}
}
// MARK：为好友生成的访问器 扩展 CachedUser {
@objc(addFriendsObject:)
@NSManaged public func addToFriends(_ value: CachedFriend)
@objc(removeFriendsObject:)
@NSManaged public func removeFromFriends(_ value: CachedFriend)
@objc(addFriends:)
@NSManaged public func addToFriends(_ values: NSSet)
@objc(removeFriends:)
@NSManaged public func removeFromFriends(_ values: NSSet)
}
extension CachedUser : Identifiable {
}
//-----
//-- 缓存用户
import Foundation
import CoreData
extension CachedFriend {
@nonobjc public class func fetchRequest() -> NSFetchRequest<CachedFriend> {
return NSFetchRequest<CachedFriend>(entityName: "CachedFriend")
}
@NSManaged public var name: String?
@NSManaged public var id: String?
@NSManaged public var users: CachedUser?
public var wrappedId: String {
id ?? "Unknown Id"
}
public var wrappedName: String {
name ?? "Unknown Name"
}
}
extension CachedFriend : Identifiable {
}
//------
//---SwiftUI查看我要数据的地方，部分好友不显示任何好友
import SwiftUI
struct DetailView: View {
let users: [CachedUser]
let user: CachedUser
@State var friendsArray: [CachedFriend] = []
@FetchRequest(sortDescriptors: []) var friendsData: FetchedResults<CachedFriend>
var body: some View {
Form {
List {
Section("Name") {
Text(user.wrappedName)
.font(.body)
}
Section("email") {
Text(user.wrappedEmail)
}
Section("Registration Date") {
Text(user.wrappedRegistered)
}
Section("Company") {
Text(user.wrappedCompany)
}
Section("Is Active") {
Image(systemName: user.isActive ? "checkmark.circle.fill" : "xmark.octagon.fill")
.foregroundColor(user.isActive ? Color.green : Color.red)
}
Section("Friends") {
List {
ForEach(friendsArray, id:\.self) {friend in
Text(friend.wrappedName)
}
}
}
}
.onAppear {
friendsArray = Array(user.cachedFriend)
}
}
}
}
//-----结束 在这里，我附上了一个 CachedUser 实体和 CachedFriend 实体的关系图像。
每个用户都有我从 json 文件中获得的朋友数组，该朋友数组包含名称和 id....
我知道我必须遍历朋友表并过滤与用户朋友数组中同名的所有名称，但我似乎无法做到这一点，我在下面尝试过，但它们不起作用，可以任何人都指向我正确的方向。谢谢
@State var friendsArray: [CachedFriend] = []
let user: CachedUser
func findFriend() {
for allFriend in friendsData {
friendsArray = user.cachedFriend.filter({ item in
item.wrappedId == allFriend.wrappedId
})
}
print(friendsArray.count)
}
json 示例
[
{
"id": "50a48fa3-2c0f-4397-ac50-64da464f9954",
"isActive": false,
"name": "Alford Rodriguez",
"age": 21,
"company": "Imkan",
"email": "alfordrodriguez@imkan.com",
"address": "907 Nelson Street, Cotopaxi, South Dakota, 5913",
"about": "Occaecat consequat elit aliquip magna laboris dolore laboris sunt officia adipisicing reprehenderit sunt. Do in proident consectetur labore. Laboris pariatur quis incididunt nostrud labore ad cillum veniam ipsum ullamco. Dolore laborum commodo veniam nisi. Eu ullamco cillum ex nostrud fugiat eu consequat enim cupidatat. Non incididunt fugiat cupidatat reprehenderit nostrud eiusmod eu sit minim do amet qui cupidatat. Elit aliquip nisi ea veniam proident dolore exercitation irure est deserunt.",
"registered": "2015-11-10T01:47:18-00:00",
"tags": [
"cillum",
"consequat",
"deserunt",
"nostrud",
"eiusmod",
"minim",
"tempor"
],
"friends": [
{
"id": "91b5be3d-9a19-4ac2-b2ce-89cc41884ed0",
"name": "Hawkins Patel"
},
{
"id": "0c395a95-57e2-4d53-b4f6-9b9e46a32cf6",
"name": "Jewel Sexton"
},
{
"id": "be5918a3-8dc2-4f77-947c-7d02f69a58fe",
"name": "Berger Robertson"
},
{
"id": "f2f86852-8f2d-46d3-9de5-5bed1af9e4d6",
"name": "Hess Ford"
},
{
"id": "6ba32d1b-38d7-4b0f-ba33-1275345eacc0",
"name": "Bonita White"
},
{
"id": "4b9bf1e5-abec-4ee3-8135-3a838df90cef",
"name": "Sheryl Robinson"
},
{
"id": "5890bacd-f49c-4ea2-b8fa-02db0e083238",
"name": "Karin Collins"
},
{
"id": "29e0f9ee-71f2-4043-ad36-9d2d6789b2c8",
"name": "Pace English"
},
{
"id": "aa1f8001-59a3-4b3c-bf5e-4a7e1d8563f2",
"name": "Pauline Dawson"
},
{
"id": "d09ffb09-8adc-48e1-a532-b99ae72473d4",
"name": "Russo Carlson"
},
{
"id": "7ef1899e-96e4-4a76-8047-0e49f35d2b2c",
"name": "Josefina Rivas"
}
]
},
【问题讨论】：
-
你什么都不用做，一个用户的朋友就是属性
user.friends。这是一个集合，所以你可能想做friendsArray = Array(user.friends) -
谢谢，我试过了 - public var cachedFriend: [CachedFriend] { let set = friends as?设置
?? [] 返回 set.sorted { $0.name! -
使用Minimal, Reproducible Example 会更容易调试。将一个简单的核心数据模型与排序所需的最少属性放在一起。
-
很难阅读评论中发布的代码，但这似乎与我的建议相去甚远
-
他，我正在更新代码，我在顶部，需要几分钟