所以我在我的应用程序中有一个部分显示你的追随者将要进行的活动。我成功的拉了追随者和相应的事件。然后我将这些事件添加到一个更大的事件对象数组中。我目前有困难删除重复我已经尝试了许多扩展,但似乎没有工作。我想这是因为数组包含不同内存地址的不同对象,所以当我比较它们时,它们并不相同,不管内容是什么。我已经搞了一段时间了,真的搞不清楚。如果有人能帮我,我将不胜感激。
这是方法获取事件并将其返回到主VC中的数组。
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()
})
}
}
}
我尝试了这些扩展,我在前面的问题中看到,但没有任何效果。
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
}
}
最佳答案
NSObject类型的类将自动为contains()方法调用isEqual()。您可以重写超类的实现以适合您的逻辑。
如果类必须继承NSObject,则使用:
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)
如果您的类不继承NSObject,请使其符合可等式协议。
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)