如何解决Swift 5- Firebase-标题中按日期分组
我的主要目标是从Firebase数据库中获取日期，并将其用作部分标题，以便我可以在该标题下加载所有具有相同日期的事件。
我希望它像这样显示在我的表格视图中：
9月-标头
-2020年9月29日-sub标头
-事件
-事件
-事件
-2020年9月30日-sub标头
-事件
-事件
-事件
这是我的主要View Controller。
import UIKit
import Foundation
import Firebase
import FirebaseDatabase
class EventsTableViewController: UIViewController {
var sectionNames: [String] = []
var events: [String: [EventsInfo]] = [:]
var datref: DatabaseReference!
var eventView = [EventsInfo]()
@IBOutlet weak var eventTableView: UITableView!
override func viewDidLoad() {
super.viewDidLoad()
getEventsFromFirebaseDB()
}
deinit {
datref.removeAllObservers()
}
private func eventsFetched(_ eventData: [EventsInfo])
{
for event in eventData
{
guard let eventNameFirstChar = event.date.first else { continue }
if var eventsForKey = events["\(eventNameFirstChar)"]
{
eventsForKey.append(event)
events["\(eventNameFirstChar)"] = eventsForKey
}
else
{
// no users are stored in dictionary for key userNameFirstChar
events["\(eventNameFirstChar)"] = [event]
}
}
// sort dictionary keys and set it in sectionNames
sectionNames = events.map { $0.key }.sorted()
print (sectionNames)
}
private func getEventsFromFirebaseDB() {
datref = Database.database().reference().child("events")
datref.observe(DataEventType.value,with: { [weak self] (snapshot) in
guard snapshot.childrenCount > 0 else { return }
var events: [EventsInfo] = []
for event in snapshot.children.allObjects as! [DataSnapshot]
{
let object = event.value as? [String: AnyObject]
let title = object?["title"]
let place = object?["place"]
let info = object?["info"]
let date = object?["date"]
let time = object?["time"]
let event = EventsInfo(title: title as! String,place: place as! String,info: info as! String,time: time as! String,date: date as! String)
events.append(event)
}
self?.eventsFetched(events)
self?.eventTableView.reloadData()
})
}
override func prepare(for segue: UIStoryboardSegue,sender: Any?) {
if segue.identifier == "showEvent"
{
if let indexPath = eventTableView.indexPathForSelectedRow
{
let destinationController = segue.destination as! EventsInfoViewController
let char = sectionNames[indexPath.section]
let event = events[char]![indexPath.row]
destinationController.EventsData = event
}
}
}
}
extension EventsTableViewController: UITableViewDataSource,UITableViewDelegate {
func numberOfSections(in tableView: UITableView) -> Int {
sectionNames.count
}
func tableView(_ tableView: UITableView,titleForHeaderInSection section: Int) -> String? {
sectionNames[section]
}
func tableView(_ tableView: UITableView,numberOfRowsInSection section: Int) -> Int {
let char = sectionNames[section]
return events[char]!.count
}
func tableView(_ tableView: UITableView,cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = eventTableView.dequeueReusableCell(withIdentifier: "eventsCell") as! EventsTableViewCell
let char = sectionNames[indexPath.section]
let event = events[char]![indexPath.row]
cell.eventTitleLabel.text = event.title
return cell
}
func tableView(_ tableView: UITableView,didSelectRowAt indexPath: IndexPath) {
performSegue(withIdentifier: "showEvent",sender: self)
}
这是我的EventsInfo文件
import Foundation
class EventsInfo {
var title: String
var place: String
var info: String
var time: String
var date: String
init(title: String,place: String,info: String,time: String,date: String) {
self.title = title
self.place = place
self.info = info
self.time = time
self.date = date
}
}
解决方法
我正在给出一个答案，希望它可以通过一个例子提供一些指导。请注意，这与Firebase无关-纯粹是tableView管理。
我们的应用程序列出了一些水果，其中标题标题是每个水果的名字
A
Apple
B
Banana
等
这是一个用于保存每个部分的数据的结构，然后是一个用于保存这些对象的类数组（tableView dataSource）
struct FruitStruct {
var sectionTitle = ""
var fruitNameArray = [String]()
}
var fruitDataSource = [FruitStruct]()
然后让我们填充数据
func setupDataSourceData() {
let fruitArray = ["Apple","Pear","Banana","Bing Cherry","Grape","Orange","Plum","Watermelon","Cantelope"]
let allFirstChars = fruitArray.map { String($0.prefix(1)) } //get all first chars for section titles
let sectionTitles = Array(Set(allFirstChars)).sorted() //eliminate dups and sort
//iterate over the unique section titles and get the fruits that are in that section
// sort and then craft structs to hold the title and the associated fruits
sectionTitles.forEach { firstChar in
let results = fruitArray.filter { $0.prefix(1) == firstChar }
let sortedFruits = results.sorted()
let fruit = FruitStruct(sectionTitle: firstChar,fruitNameArray: sortedFruits)
fruitDataSource.append(fruit)
}
//this code is to just output the data to console so you can see what it
// looks like. Remove it.
for fruitData in fruitDataSource {
print(fruitData.sectionTitle)
let fruits = fruitData.fruitNameArray
for fruitName in fruits {
print(" \(fruitName)")
}
}
}
最后，使用tableView委托方法从dataSource填充tableView
//
//handle sections
//
func numberOfSections(in tableView: UITableView) -> Int {
return self.fruitDataSource.count
}
func tableView(_ tableView: UITableView,titleForHeaderInSection section: Int) -> String? {
let title = self.fruitDataSource[section].sectionTitle
return title
}
//
//handleTableView rows
//
func tableView(_ tableView: UITableView,numberOfRowsInSection section: Int) -> Int {
let rowsInSection = self.fruitDataSource[section].fruitNameArray.count
return rowsInSection
}
func tableView(_ tableView: UITableView,cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "cellReuseIdentifier",for: indexPath)
let text = self.fruitDataSource[indexPath.section].fruitNameArray[indexPath.row]
cell.textLabel?.text = text
return cell
}
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