保存在swift4

我想保存在此应用程序的表情符号,我在苹果的书中学到什么,但问题是,我不明白书中的下一步的文件管理器,保存在swift4

创建一个静态loadSampleEmojis()方法,该方法将创建并返回预定义的[表情符号]集合。您可以使用EmojiTableViewController中分配给表情符号的列表作为项目列表。

更新表情符号将被初始化为空的集合,而不是一个大样本collection.When的viewDidLoad中()方法被调用,你应该检查文件/目录表情符号使用loadFromfile(任何先前保存的绘文字对象)。如果他们被发现将它们分配给emojis.if不会将emojis分配给loadSampleEmojis()的结果。

花点时间思考何时可能适合保存您的Emoji对象。 在这种情况下,您的日期的中心点是emojis携带Emojitableviewcontroller,意味着只要emojis属性发生更改,就可以调用saveToFile(emojis:)。 接下来,请考虑何时载入您的归档Emoji objects.again,在这种简单的情况下,真正只有一点需要将归档数据取消归档:何时第一个视图载入。您应该已经调用了这个方法在第一个视图控制器viewdidload()中。

这是我写的,直到如今,

import Foundation 

struct Emoji : Codable {

var symbol : String

var name : String

var description : String

var usage : String

static let documentsdirectory = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!

static let archiveurl = documentsdirectory.appendingPathComponent("emojis").appendingPathExtension("plist")

static func SaveToFile (emojis: [Emoji]) {

let propetyencod = PropertyListEncoder()

let encodemoj = try? propetyencod.encode(emojis)

try? encodemoj?.write(to : archiveurl , options : .noFileProtection)

}

static func loadeFromFile() -> [Emoji] {

let propetydicod = PropertyListDecoder()

if let retrivdate = try? Data(contentsOf: archiveurl),

let decodemoj = try?

propetydicod.decode(Array<Emoji>.self, from: retrivdate){

return decodemoj

}

return [Emoji]()

}

}

import UIKit

class emojiTableViewController: UITableViewController {

var emojis : [Emoji] = [

Emoji(symbol: "", name: "Grinning Face",

description: "A typical smiley face.", usage: "happiness"),

Emoji(symbol: "", name: "Confused Face",

description: "A confused, puzzled face.", usage: "unsure what to think; displeasure"),

Emoji(symbol: "", name: "Heart Eyes",

description: "A smiley face with hearts for eyes.",

usage: "love of something; attractive"),

Emoji(symbol: "", name: "Police Officer",

description: "A police officer wearing a blue cap with a gold badge.", usage: "person of authority"),

Emoji(symbol: "", name: "Turtle", description:

"A cute turtle.", usage: "Something slow"),

Emoji(symbol: "", name: "Elephant", description:

"A gray elephant.", usage: "good memory"),

Emoji(symbol: "", name: "Spaghetti",

description: "A plate of spaghetti.", usage: "spaghetti"),

Emoji(symbol: "", name: "Die", description: "A single die.", usage: "taking a risk, chance; game"),

Emoji(symbol: "⛺️", name: "Tent", description: "A small tent.", usage: "camping"),

Emoji(symbol: "", name: "Stack of Books",

description: "Three colored books stacked on each other.",

usage: "homework, studying"),

Emoji(symbol: "", name: "Broken Heart",

description: "A red, broken heart.", usage: "extreme sadness"), Emoji(symbol: "", name: "Snore",

description:

"Three blue \'z\'s.", usage: "tired, sleepiness"),

Emoji(symbol: "", name: "Checkered Flag",

description: "A black-and-white checkered flag.", usage:

"completion")]

override func viewDidLoad() {

super.viewDidLoad()

navigationItem.leftBarButtonItem = editButtonItem

tableView.rowHeight = UITableViewAutomaticDimension

tableView.estimatedRowHeight = 52.0

// Uncomment the following line to preserve selection between presentations

// self.clearsSelectionOnViewWillAppear = false

// Uncomment the following line to display an Edit button in the navigation bar for this view controller.

// self.navigationItem.rightBarButtonItem = self.editButtonItem()

}

override func didReceiveMemoryWarning() {

super.didReceiveMemoryWarning()

// Dispose of any resources that can be recreated.

}

// MARK: - Table view data source

override func numberOfSections(in tableView: UITableView) -> Int {

// #warning Incomplete implementation, return the number of sections

return 1

}

override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {

// #warning Incomplete implementation, return the number of rows

if section == 0 {

return emojis.count

}else{

return 0

}

}

override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {

let cell = tableView.dequeueReusableCell(withIdentifier: "emojicell", for: indexPath) as! cellviewTableViewCell

let emoji = emojis[indexPath.row]

cell.update(with: emoji)

cell.showsReorderControl = true

return cell

}

@IBAction func editbutton(_ sender: UIBarButtonItem) {

let tablevieweditingmod = tableView.isEditing

tableView.setEditing(!tablevieweditingmod, animated: true)

}

override func tableView(_ tableView: UITableView, editingStyleForRowAt indexPath: IndexPath) -> UITableViewCellEditingStyle {

return.delete

}

override func viewWillAppear(_ animated: Bool) {

tableView.reloadData()

}

/*

// Override to support conditional editing of the table view.

override func tableView(_ tableView: UITableView, canEditRowAt indexPath: IndexPath) -> Bool {

// Return false if you do not want the specified item to be editable.

return true

}

*/

// Override to support editing the table view.

override func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCellEditingStyle, forRowAt indexPath: IndexPath) {

if editingStyle == .delete {

// Delete the row from the data source

emojis.remove(at: indexPath.row)

tableView.deleteRows(at: [indexPath], with: .automatic)

} else if editingStyle == .insert {

// Create a new instance of the appropriate class, insert it into the array, and add a new row to the table view

}

}

// Override to support rearranging the table view.

override func tableView(_ tableView: UITableView, moveRowAt fromIndexPath: IndexPath, to: IndexPath) {

let movedEmoji = emojis.remove(at: fromIndexPath.row)

emojis.insert(movedEmoji, at: to.row)

tableView.reloadData()

}

/*

// Override to support conditional rearranging of the table view.

override func tableView(_ tableView: UITableView, canMoveRowAt indexPath: IndexPath) -> Bool {

// Return false if you do not want the item to be re-orderable.

return true

}

*/

/*

// MARK: - Navigation

// In a storyboard-based application, you will often want to do a little preparation before navigation

override func prepare(for segue: UIStoryboardSegue, sender: Any?) {

// Get the new view controller using segue.destinationViewController.

// Pass the selected object to the new view controller.

}

*/

override func prepare(for segue: UIStoryboardSegue, sender: Any?) {

if segue.identifier == "editcell"{

let indexpath = tableView.indexPathForSelectedRow!

let emoji = emojis[indexpath.row]

let edittableview = segue.destination as! addTableViewController

edittableview.emoji = emoji

}

}

@IBAction func unwindToemojitableview(segue: UIStoryboardSegue){

guard segue.identifier == "saveun" else {return}

let sourseviewcontroler = segue.source as! addTableViewController

if let emoji = sourseviewcontroler.emoji{

if let selectedindexpath = tableView.indexPathForSelectedRow{

emojis[selectedindexpath.row] = emoji

tableView.reloadRows(at: [selectedindexpath], with: .none)

}else {

let newindexpath = IndexPath(row: emojis.count, section: 0)

emojis.append(emoji)

tableView.insertRows(at: [newindexpath], with: .automatic)

}

}

}

}

import UIKit

class addTableViewController: UITableViewController {

var emoji : Emoji?

@IBOutlet weak var symboltexfiel: UITextField!

@IBOutlet weak var nametexfiel: UITextField!

@IBOutlet weak var descriptexfiel: UITextField!

@IBOutlet weak var usagetexfiel: UITextField!

@IBOutlet weak var savebutt: UIBarButtonItem!

override func viewDidLoad() {

super.viewDidLoad()

if let emoji = emoji{

symboltexfiel.text = emoji.symbol

nametexfiel.text = emoji.name

descriptexfiel.text = emoji.description

usagetexfiel.text = emoji.usage

}

ubdatesavebutt()

}

override func prepare(for segue: UIStoryboardSegue, sender: Any?) {

super.prepare(for: segue, sender: sender)

guard segue.identifier == "saveun" else {return}

let sym = symboltexfiel.text ?? ""

let nam = nametexfiel.text ?? ""

let de = descriptexfiel.text ?? ""

let use = usagetexfiel.text ?? ""

emoji = Emoji(symbol: sym, name: nam, description: de, usage: use)

}

func ubdatesavebutt() {

let symbol = symboltexfiel.text ?? ""

let name = nametexfiel.text ?? ""

let descr = descriptexfiel.text ?? ""

let use = usagetexfiel.text ?? ""

savebutt.isEnabled = !symbol.isEmpty && !name.isEmpty && !descr.isEmpty && !use.isEmpty

}

@IBAction func ediittex(_ sender: UITextField) {

ubdatesavebutt()

}

}

import UIKit

class cellviewTableViewCell: UITableViewCell {

@IBOutlet weak var symbollabel: UILabel!

@IBOutlet weak var namelabel: UILabel!

@IBOutlet weak var descriptionlabel: UILabel!

override func awakeFromNib() {

super.awakeFromNib()

// Initialization code

}

override func setSelected(_ selected: Bool, animated: Bool) {

super.setSelected(selected, animated: animated)

// Configure the view for the selected state

}

func update(with emoji : Emoji) {

symbollabel.text = emoji.symbol

namelabel.text = emoji.name

descriptionlabel.text = emoji.description

}

}

回答:

首先,您将需要添加静态方法,将返回[表情],并包含您的表情符号预设(从表情符表视图控制器)。

static func loadSampleEmojis() -> [Emoji]{ 

return [Your emojis array]}

之后,在表情符号表视图控制器,你需要定义像

var emojis = [Emoji]() 

接下来,在viedDidLoad(表情符号),您需要检查是否有任何数据你的ArchiveURL?如果是 - 将其分配到您的表情符号,否则分配预设。

if let savedEmojis = Emoji.loadFromFile() { 

emojis = savedEmojis

} else {

emojis = Emoji.loadSampleEmoji()}

而在这之后添加

Emoji.saveToFile(emoji: emojis) 

到的tableView(_,moveRowAt:,到:),的tableView(editingStyle)和unwindSegue。

此外,您还需要更正:在viewDidLoad中

static func loadFromFile() -> [Emoji]? {..} 

或控制流将无法正常工作。

以上是 保存在swift4 的全部内容, 来源链接: utcz.com/qa/265557.html

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