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问题描述

如何对从该datestamp字段动态生成的以下部分进行排序?例如调用的部分2021-11-3需要显示在上面的tableview中2021-11-2

日期戳格式: 2021-11-3

var sections = [mySections]()
var structure = [myStructure]()

private func fetchJSON() {
    
    guard let url = URL(string: "test.com")
    else { return }
    
    var request = URLRequest(url: url)
    request.httpMethod = "POST"
    request.httpBody = "id=\1".data(using: .utf8)
    

URLSession.shared.dataTask(with: request) { data, _, error in
guard let data = data else { return }
                
do {
  let decoder = JSONDecoder()
  self.structure.sort { $0. datestamp > $1.datestamp }
  let res = try decoder.decode([myStructure].self, from: data)
  let grouped = Dictionary(grouping: res, by: { $0. datestamp })
  let keys = grouped.keys.sorted()
self.sections = keys.map({mySections(date: $0, items: grouped[$0]!
                    
)})
  DispatchQueue.main.async {
  self.tableView.reloadData()
}
        }
        
        catch {
            print(error)
        }
    }.resume()
 }

我尝试过以下操作,self.sections但它没有做任何事情:

self.sections.sorted { $0.date > $1.date }

结构:

struct mySections {
    let date : String
    var items : [myStructure]
}


struct myStructure: Decodable {
    
    let recordid: Int
    let testname: Int
    let datestamp: String
}

数据示例:

[
  { 
    "recordid": 1,
    "testname": "Jen",
    "datestamp": "2021-11-3"
  },
  {
    "recordid": 1,
    "testname": "Jake",
    "datestamp": "2021-11-2"
  }
]

标签: swift

解决方案


现在,您正在structure根据 进行排序dateTimeStamp,它什么也不做,因为其中structure没有任何数据。

在我的游乐场示例中,就像您的代码一样,我使用了Dictionary(grouped:). 然后,我将map那些结果mySectionssort.date

最后的结果print是:

[“2021-11-4”、“2021-11-3”、“2021-11-2”]

let data = """
[
  {
    "recordid": 1,
    "testname": "Jake",
    "datestamp": "2021-11-2"
  },
  {
    "recordid": 2,
    "testname": "Jen",
    "datestamp": "2021-11-3"
  },
      {
        "recordid": 3,
        "testname": "Bob",
        "datestamp": "2021-11-3"
      },
      {
        "recordid": 4,
        "testname": "Bill",
        "datestamp": "2021-11-4"
      }
]
""".data(using: .utf8)!

struct mySections {
    let date : String
    var items : [myStructure]
}


struct myStructure: Decodable {
    let recordid: Int
    let testname: String
    let datestamp: String
}

var sections = [mySections]()
var structure = [myStructure]()

do {
    let decoder = JSONDecoder()
    let res = try decoder.decode([myStructure].self, from: data)
    let grouped = Dictionary(grouping: res, by: { $0.datestamp })
    sections = grouped.map { mySections(date: $0.key, items: $0.value) }
        .sorted { $0.date > $1.date }
    print(sections.map(\.date))
} catch {
    print(error)
}

可能值得注意的是,现在您的日期以统一格式存储,非常适合基于字符串的排序。但是,如果您的端点返回的日期格式不统一(如2021-11-042021-11-3),您可能希望转换为实际的Date第一个日期并根据该日期进行排序。


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