如何过滤UITableView中显示的信息类型?迅捷JSON [英] How to filter what type of information is shown in a UITableView | Swift JSON

问题描述

我有一个UITableView从JSON获取信息，问题是我只想显示UITableView中的String值，但不包括任何Doubles

I have a UITableView that is getting information from JSON the issue is I would like to only show the String values in the UITableView excluding any Doubles

JSON解码器的结构为:

The structure of the JSON decoder is:

struct PurchaseTotals: Codable {
    var sumTotal: Double?
    var animal: String?
    var name: String?
    enum CodingKeys: String, CodingKey {
        case sumTotal = "sumTotal"
        case animal = "animal"
        case sumTotal = "name"
    }

    lazy var formattedSumTotal: String? =  {
        if let sumTotal = sumTotal {
            let formatter = NumberFormatter()
            formatter.numberStyle = .decimal
            let str = formatter.string(from: NSNumber(value: sumTotal))
            return str
        }
        return nil
    }()
}

在cellForRowAt中，我用变量portfolio定义结构:

And in the cellForRowAt I define the structure with the variable portfolio:

var portfolio: PurchaseTotals

cellForRowAt中的单元格正在填充，并通过以下方式在UITableView中显示.

And in cellForRowAt the cells are being populated and are being shown in the UITableView the following way.

首先，我使用变量structure定义JSON结构:

First I define the JSON structure with the variable structure:

var structure = [PurchaseTotals]()

然后我将变量portfolio设置为等于structure[indexPath.row]

Then I set the variable portfolio equal to structure[indexPath.row]

portfolio = structure[indexPath.row]

JSON如下:

[{"name":"Jake","animal":"dog"},{"name":"Mary","animal":"cat"},{"sumTotal":100}]

现在的平均单元数为3，但我希望有2个单元，不包括sumTotal.

Meaning the number of cells right now is 3 but I would like 2 cells, excluding the sumTotal.

更新:

import UIKit


class TableViewController: UITableViewController {


    var dataSource  = [PurchaseTotals]()


    var structure = [PurchaseTotals]() {
        didSet {
            dataSource = structure.filter({ $0.sumTotal == nil })
            self.tableView.reloadData()
        }
    }

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

    override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCell(withIdentifier: "cellID", for: indexPath) as! ScheduleCell
        var portfolio = dataSource[indexPath.row]
        return cell
    }

struct PurchaseTotals: Codable {
    var sumTotal: Double?
    var animal: String?
    var name: String?


lazy var formattedSumTotal: String? =  {
    if let sumTotal = sumTotal {
        let formatter = NumberFormatter()
        formatter.numberStyle = .decimal
        let str = "$" + formatter.string(from: NSNumber(value: sumTotal))!
        return str
    }
    return nil
}()

}

推荐答案

创建一个名为dataSource的单独变量，该变量仅包含structure中具有sumTotal = nil的那些元素，即

Create a separate variable named dataSource that will contain only those elements from structure having sumTotal = nil, i.e

var structure = [PurchaseTotals]() {
    didSet {
        dataSource = structure.filter({ $0.sumTotal == nil })
        self.tableView.reloadData()
    }
}
var dataSource  = [PurchaseTotals]()

在上面的代码中，在获取API响应后填充structure array时，dataSource array将在structure的didSet中更新.

In the above code, the dataSource array will be updated in didSet of structure when the structure array is filled after getting the API response.

因此，structure将包含来自API响应的实际数据.并且dataSource将包含来自structure的已过滤内容.

So, structure will contain the actual data from API response. And dataSource will contain the filtered content from structure.

现在，在

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

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    let portfolio = dataSource[indexPath.row]
    //rest of the code...
}

---

注意:如果属性名称与 API密钥完全匹配，则不需要enum CodingKeys.因此struct PurchaseTotals可以重写为

---

Note: There is no need for enum CodingKeys if the property names exactly match the API keys. So the struct PurchaseTotals can be rewritten as,

struct PurchaseTotals: Codable {
    var sumTotal: Double?
    var animal: String?
    var name: String?

    lazy var formattedSumTotal: String? =  {
        //rest of the code...
    }()
}

使用示例 JSON 代替 API 这样的响应，

Use sample JSON instead of API response like,

let str = """
[{"name":"Jake","animal":"dog"},{"name":"Mary","animal":"cat"},{"sumTotal":100}]
"""
if let data = str.data(using: .utf8) {
    do {
        structure = try JSONDecoder().decode([PurchaseTotals].self, from: data)
        print(structure)
    } catch {
        print(error)
    }
}

这是对我来说很好的整个代码，

Here is the whole code that is working fine for me,

struct PurchaseTotals: Codable {
    var sumTotal: Double?
    var animal: String?
    var name: String?
    
    lazy var formattedsumTotal: String? =  {
        if let sumTotal = sumTotal {
            let formatter = NumberFormatter()
            formatter.numberStyle = .decimal
            let str = formatter.string(from: NSNumber(value: sumTotal))
            return str
        }
        return nil
    }()
}

class TableViewController: UITableViewController {
    var structure = [PurchaseTotals]() {
        didSet {
            dataSource = structure.filter({ $0.sumTotal == nil })
            self.tableView.reloadData()
        }
    }
    var dataSource  = [PurchaseTotals]()
    
    override func viewDidLoad() {
        super.viewDidLoad()
        let str = """
        [{"name":"Jake","animal":"dog"},{"name":"Mary","animal":"cat"},{"sumTotal":100}]
        """
        if let data = str.data(using: .utf8) {
            do {
                structure = try JSONDecoder().decode([PurchaseTotals].self, from: data)
            } catch {
                print(error)
            }
        }
    }
    
    override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return dataSource.count
    }
    
    override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath)
        cell.textLabel?.text = dataSource[indexPath.row].name
        return cell
    }
}

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