如何对从datestamp字段动态生成的以下部分进行排序?例如,名为2021-11-3的部分需要显示在2021-11-2上面的表视图中。
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()
}我尝试过在self.sections下执行以下操作,但它什么也不做:
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"
}
]发布于 2021-11-03 19:28:28
现在,您正在基于structure对dateTimeStamp进行排序,因为structure中没有任何数据。
在我的操场示例中,就像您的代码一样,我使用了Dictionary(grouped:)。然后,我通过map将这些结果传递给mySections和sort。
最后,print的结果是:
"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)
}值得注意的是,现在您的日期是以统一格式存储的,这种格式对于基于字符串的排序非常有效。但是,如果端点返回格式不一致的日期(如2021-11-04和2021-11-3),则需要首先转换为实际的Date,并根据此进行排序。
https://stackoverflow.com/questions/69830045
复制相似问题