所以我的应用程序中有一个部分显示了您的关注者将要访问的事件。我成功地拉动了粉丝，并有相应的事件。然后，我将这些事件添加到更大的事件对象数组中。我目前在删除重复项时遇到了问题，我尝试了许多扩展程序，但它似乎并没有起作用。我认为这是因为数组包含具有不同内存地址的不同对象，因此当我比较它们时，无论内容是什么，它们都不相同。我现在已经搞砸了一段时间了，并且无法解决任何问题。如果有人能帮助我，我会很感激。
这是抓取事件并将它们返回到主VC中的数组的方法。
static func showFollowingEvent(for followerKey: String,completion: @escaping (Event) -> Void) {
//getting firebase root directory
let ref = Database.database().reference()
ref.child("users").child(followerKey).child("Attending").observeSingleEvent(of: .value, with: { (attendingSnapshot) in
print(attendingSnapshot)
guard var eventKeys = attendingSnapshot.children.allObjects as? [DataSnapshot] else{return}
for event in eventKeys{
let dispatchGroup = DispatchGroup()
dispatchGroup.enter()
EventService.show(forEventKey: event.key, completion: { (event) in
dispatchGroup.leave()
completion(event!)
})
}
}) { (err) in
print("couldn't grab event info",err)
}
} print("couldn't grab event info",err)
}
}
这是接收事件并在获取事件时重新加载collectionView的函数。
@objc func grabFriendsEvents(){
print("Attempting to see where your friends are going")
UserService.following { (user) in
for following in user {
print(following.username as Any)
PostService.showFollowingEvent(for: following.uid, completion: { (event) in
self.friendsEvents.append(event)
// self.friendsEvents.append(contentsOf: event)
// leave here
self.allEvents2["Friends Events"] = self.friendsEvents.removeDuplicates()
self.collectionView?.reloadData()
})
}
}
}
我尝试过这些扩展，这是我在之前的问题中看到的，没有任何效果。
extension Array where Element: Equatable {
func removeDuplicates() -> [Element] {
var result = [Element]()
for value in self {
if result.contains(value) == false {
result.append(value)
}
}
return result
}
mutating func removeDuplicatesTwo() {
var result = [Element]()
for value in self {
if !result.contains(value) {
result.append(value)
}
}
self = result
}
}
import Foundation
import FirebaseDatabase.FIRDataSnapshot
@objc(Event)
class Event:NSObject{
var key: String?
let currentEventName: String
let currentEventImage: String
let currentEventPromo: String?
let currentEventDescription: String
//nested properties
let currentEventStreetAddress: String
let currentEventCity: String
let currentEventState: String
let currentEventDate: String?
let currentEventEndDate: String?
let currentEventTime: String?
let currentEventEndTime: String?
let currentEventZip: Int
var category: String
//nested properties stop
var currentAttendCount: Int
var isAttending = false
var eventDictionary: [String: Any]{
let dateDict = ["start:date":currentEventDate, "start:time": currentEventTime,"end:time":currentEventEndTime, "end:date": currentEventEndDate]
return ["event:name":currentEventName,"event:imageURL" : currentEventImage,
"event:description": currentEventDescription, "attend:count": currentAttendCount,
"event:street:address": currentEventStreetAddress,"event:zip": currentEventZip,
"event:state": currentEventState, "event:city": currentEventCity, "event:promo": currentEventPromo ?? "", "event:date": dateDict, "event:category":category]
}
init(currentEventKey: String, dictionary: [String:Any]) {
self.key = currentEventKey
self.currentEventName = dictionary["event:name"] as? String ?? ""
self.currentEventImage = dictionary["event:imageURL"] as? String ?? ""
self.currentEventDescription = dictionary["event:description"] as? String ?? ""
self.currentEventPromo = dictionary["event:promo"] as? String ?? ""
self.currentAttendCount = dictionary["attend:count"] as? Int ?? 0
self.category = dictionary["event:category"] as? String ?? ""
//nested properties
self.currentEventStreetAddress = dictionary["event:street:address"] as? String ?? ""
self.currentEventCity = dictionary["event:city"] as? String ?? ""
self.currentEventState = dictionary["event:state"] as? String ?? ""
self.currentEventZip = dictionary["event:zip"] as? Int ?? 0
let eventDate = dictionary["event:date"] as? [String: Any]
self.currentEventDate = eventDate?["start:date"] as? String ?? ""
self.currentEventTime = eventDate?["start:time"] as? String ?? ""
self.currentEventEndTime = eventDate?["end:time"] as? String ?? ""
self.currentEventEndDate = eventDate?["end:date"] as? String ?? ""
}
init?(snapshot: DataSnapshot) {
guard let dict = snapshot.value as? [String : Any],
let currentEventName = dict["event:name"] as? String,
let currentEventImage = dict["event:imageURL"] as? String,
let currentEventDescription = dict["event:description"] as? String,
let currentEventPromo = dict["event:promo"] as? String,
let category = dict["event:category"] as? String,
let currentEventStreetAddress = dict["event:street:address"] as? String,
let currentEventCity = dict["event:city"] as? String,
let currentEventState = dict["event:state"] as? String,
let currentEventZip = dict["event:zip"] as? Int,
let currentAttendCount = dict["attend:count"] as? Int,
let eventDate = dict["event:date"] as? [String: Any],
let currentEventDate = eventDate["start:date"] as? String,
let currentEventEndDate = eventDate["end:date"] as? String,
let currentEventTime = eventDate["start:time"] as? String,
let currentEventEndTime = eventDate["end:time"] as? String
else { return nil }
self.key = snapshot.key
self.currentEventName = currentEventName
self.currentEventImage = currentEventImage
self.currentEventDescription = currentEventDescription
self.currentEventStreetAddress = currentEventStreetAddress
self.currentEventCity = currentEventCity
self.currentEventState = currentEventState
self.currentEventZip = currentEventZip
self.currentAttendCount = currentAttendCount
self.currentEventPromo = currentEventPromo
self.currentEventDate = currentEventDate
self.currentEventTime = currentEventTime
self.currentEventEndTime = currentEventEndTime
self.category = category
self.currentEventEndDate = currentEventEndDate
}
static func ==(lhs: Event, rhs: Event) -> Bool {
return lhs.key == rhs.key
}
}
答案 0 :(得分：1)
您必须使Event类符合Equatable协议
答案 1 :(得分：1)
NSObject类的类将自动为contains（）方法调用isEqual（）。您可以覆盖超类的实现以适合您的逻辑。
如果你的类要继承NSObject，那么使用：
class Event: NSObject {
var key: String?
init(key: String) {
self.key = key
}
override func isEqual(_ object: Any?) -> Bool {
guard let event = object as? Event else { return false }
return self.key == event.key
}
}
var event = Event(key: "abc")
var eventCopy = Event(key: "abc")
extension Array where Element:Equatable {
func removeDuplicates() -> [Element] {
return reduce(into: []) { result, element in
if !result.contains(element) {
result.append(element)
}
}
}
}
var events = [event, eventCopy]
events = events.removeDuplicates()
print(events.count)
如果您的类没有继承NSObject，请使其符合Equatable协议。
class Event: Equatable {
var key: String?
init(key: String) {
self.key = key
}
static func ==(lhs: Event, rhs: Event) -> Bool {
return lhs.key == rhs.key
}
}
var event = Event(key: "abc")
var eventCopy = Event(key: "abc")
extension Array where Element:Equatable {
func removeDuplicates() -> [Element] {
var result = [Element]()
for value in self {
if result.contains(value) == false {
result.append(value)
}
}
return result
}
}
var events = [event, eventCopy]
events = events.removeDuplicates()
print(events.count)