Question

我有表格视图，显示项目列表。每次选择一行时，都会添加一个复选标记，相应的金额会添加到var total.

如果选择了另一行，则删除前一行的复选标记，减去前一行的金额。

我正在尝试保存和检索NSUserdefaults以下信息：选中行的复选标记（如果选择了任何行）， var total的值， indexPathForCellSelected，，已选择的特定行的数量。

import UIKit
class EighthViewController: UIViewController, UITableViewDelegate,UITableViewDataSource {



struct Item {
    var name:String // name of the row
    var selected:Bool // whether is selected or not
    var amount: Int // value of the item
}

var frequency = [

    Item(name:"Every week",selected: false, amount: 30),
    Item(name:"Every 2 weeks",selected: false, amount: 30),
    Item(name:"Every 4 weeks",selected: false, amount: 30),
    Item(name:"Once",selected: false, amount: 40),
    Item(name:"End of tenancy cleaning", selected: false, amount: 44)
]

var total = 0
var indexPathForCellSelected: NSIndexPath?
@IBOutlet weak var tableView: UITableView!
let indexKey = "indexPathForCellSelected"
let totalKey = "total"
let amountKey = "amount"



override func viewDidLoad() {
        }

override func viewDidAppear(animated: Bool) {
    super.viewDidAppear(animated)

    // retrieve indexPathForCellSelected from NSUserDefaults
    if let retrievedIndexPath = NSUserDefaults.standardUserDefaults().objectForKey(indexKey) {
        let data1 = NSUserDefaults.standardUserDefaults().objectForKey(indexKey) as? NSData
            indexPathForCellSelected = NSKeyedUnarchiver.unarchiveObjectWithData(data1!) as? NSIndexPath

            // retrieve total from NSUserDefaults
            if let totalRetrieved = NSUserDefaults.standardUserDefaults().objectForKey(totalKey) as? Int {
        total = totalRetrieved
                print(total)
        }

        //
        if let itemAmount =  NSUserDefaults.standardUserDefaults().objectForKey(amountKey) as? Int {
            let myIndexpath = indexPathForCellSelected?.row
                frequency[myIndexpath!].amount = itemAmount

             **UPDATED:** tableView.cellForRowAtIndexPath(indexPathForCellSelected!)?.accessoryType = .Checkmark

        }
    }
}


func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    return frequency.count
}

func numberOfSectionsInTableView(tableView: UITableView) -> Int {
    return 1
}

// configure the cell
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath)
    -> UITableViewCell     {
    let cell = tableView.dequeueReusableCellWithIdentifier("Cell")
        cell?.textLabel?.text = frequency[indexPath.row].name
    return cell!
}

func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {

    if !frequency[indexPath.row].selected {

        // this avoid set initial value for the first time
        if let index = indexPathForCellSelected {
            // clear the previous cell
            frequency[index.row].selected = false
            tableView.cellForRowAtIndexPath(index)?.accessoryType = .None
            self.total -= frequency[index.row].amount
            print(total)
        }

        // mark the new one
        frequency[indexPath.row].selected = true
        tableView.cellForRowAtIndexPath(indexPath)?.accessoryType = .Checkmark

        indexPathForCellSelected = indexPath
        self.total += frequency[indexPath.row].amount
        print(total)

       if indexPathForCellSelected != nil { // check if there is a selected row in the table

        //save indexPathForCellSelected in NSUserDefaults
     let data = NSKeyedArchiver.archivedDataWithRootObject(indexPathForCellSelected!)
        NSUserDefaults.standardUserDefaults().setObject(data, forKey: indexKey)

            //save total in NSUserDefaults
                NSUserDefaults.standardUserDefaults().setObject(total, forKey: totalKey)

            // save amount in NSUserDefaults
                NSUserDefaults.standardUserDefaults().setObject(frequency[indexPath.row].amount, forKey: amountKey)

        } // end of if indexPathForCellSelected
    }
 }

}

此处是应用的屏幕截图：link

Answer 1

此代码有效。如果有人有更好的实施，请在答案部分发布。

class EighthViewController: UIViewController, UITableViewDelegate,UITableViewDataSource {



struct Item {
    var name:String // name of the row
    var selected:Bool // whether is selected or not
    var amount: Int // value of the item
}

var frequency = [

    Item(name:"Every week",selected: false, amount: 30),
    Item(name:"Every 2 weeks",selected: false, amount: 30),
    Item(name:"Every 4 weeks",selected: false, amount: 30),
    Item(name:"Once",selected: false, amount: 40),
    Item(name:"End of tenancy cleaning", selected: false, amount: 44)
]

var total = 0
var indexPathForCellSelected: NSIndexPath?
@IBOutlet weak var tableView: UITableView!
let indexKey = "indexPathForCellSelected"
let totalKey = "total"
let amountKey = "amount"



override func viewDidLoad() {
}

override func viewDidAppear(animated: Bool) {
    super.viewDidAppear(animated)

    // retrieve indexPathForCellSelected from NSUserDefaults
if let retrievedIndexPath = NSUserDefaults.standardUserDefaults().dataForKey(indexKey) {
if let data1 = NSKeyedUnarchiver.unarchiveObjectWithData(retrievedIndexPath) as? NSIndexPath{
    indexPathForCellSelected = data1
}




        // retrieve total from NSUserDefaults
        if let totalRetrieved = NSUserDefaults.standardUserDefaults().objectForKey(totalKey) as? Int {
            total = totalRetrieved
            print(total)
        }

        //
      if let itemAmount =  NSUserDefaults.standardUserDefaults().objectForKey(amountKey) as? Int {
            let myIndexpath = indexPathForCellSelected?.row
            frequency[myIndexpath!].amount = itemAmount

            tableView.cellForRowAtIndexPath(indexPathForCellSelected!)?.accessoryType = .Checkmark

        }
    }
}


func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    return frequency.count
}

func numberOfSectionsInTableView(tableView: UITableView) -> Int {
    return 1
}

// configure the cell
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath)
    -> UITableViewCell     {
        let cell = tableView.dequeueReusableCellWithIdentifier("Cell")
        cell?.textLabel?.text = frequency[indexPath.row].name
        return cell!
}

func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {

    if !frequency[indexPath.row].selected {

        // this avoid set initial value for the first time
        if let index = indexPathForCellSelected {
            // clear the previous cell
            frequency[index.row].selected = false
                tableView.cellForRowAtIndexPath(index)?.accessoryType = .None
                    self.total -= frequency[index.row].amount
                        print(total)
        }

        // mark the new one
        frequency[indexPath.row].selected = true
            tableView.cellForRowAtIndexPath(indexPath)?.accessoryType = .Checkmark
                self.total += frequency[indexPath.row].amount
                    indexPathForCellSelected = indexPath
        print(total)

        if indexPathForCellSelected != nil { // check if there is a selected row in the table

            //save indexPathForCellSelected in NSUserDefaults
            let data = NSKeyedArchiver.archivedDataWithRootObject(indexPathForCellSelected!)
            NSUserDefaults.standardUserDefaults().setObject(data, forKey: indexKey)

            //save total in NSUserDefaults
            NSUserDefaults.standardUserDefaults().setObject(total, forKey: totalKey)

            // save amount in NSUserDefaults
    NSUserDefaults.standardUserDefaults().setObject(frequency[indexPath.row].amount, forKey: amountKey)

        } // end of if indexPathForCellSelected
    }
  }

}

将tableView内容保存到NSUserDefaults Swift

1 个答案: