如何反序列化具有基于日期的属性名称的 Json？

Question

I have the following Json snippet being returned from an API. I want to deserialize into a Typed class however the property names are dates so they change with each call.

How do I do this?

"watts": {
        "2022-12-19 08:14:00": 0,
        "2022-12-19 09:00:00": 48,
        "2022-12-19 10:00:00": 114,
        "2022-12-19 11:00:00": 140,
        "2022-12-19 12:00:00": 140,
        "2022-12-19 13:00:00": 132,
        "2022-12-19 14:00:00": 105,
        "2022-12-19 15:00:00": 53,
        "2022-12-19 15:44:00": 0,
        "2022-12-20 08:14:00": 0,
        "2022-12-20 09:00:00": 230,
        "2022-12-20 10:00:00": 383,
        "2022-12-20 11:00:00": 453,
        "2022-12-20 12:00:00": 453,
        "2022-12-20 13:00:00": 384,
        "2022-12-20 14:00:00": 238,
        "2022-12-20 15:00:00": 81,
        "2022-12-20 15:44:00": 0
    }

Answer 1

the easiest way is to deserialize to a dictionary

Dictionary<DateTime, int> wattsDict = JObject.Parse(json)["watts"]
                                      .ToObject<Dictionary<DateTime, int>>();

but if you need more typed data, you can create a list

List<Watt> watts = ((JObject)JObject.Parse(json)["watts"]).Properties()
                                   .Select(i => new Watt { Date = DateTime.Parse(i.Name), 
                                                           Quantity = (int)i.Value }
                                    ).ToList();

public class Watt
{
    public DateTime Date { get; set; }
    public int Quantity { get; set; }
}

Answer 2

I am not familiar with newtonsoft and it seem that newtonsoft has more features than the JsonSerializer . Nonetheless i wondered how the requirement above could be done with the "built-in" System.Text.Json.Serializer . And maybe others might find it usefull

The first thing i stumbled over was that

• the date-time-string "2022-12-19 08:14:00" could not be parsed out of the box,
• after changing it to "2022-12-19T08:14:00" it is parseable.

GetWattsJson() returns the json object with the changed date format.

public static string GetWattsJson()
{
    // This format "2022-12-19 08:14:00" resulted in "JSON value not supported format."
    // This format "2008-03-12T11:07:31" works out of the box
    string json =""" 
        {
        "2022-12-19T08:14:00": 0,
        "2022-12-19T09:00:00": 48,
        "2022-12-19T10:00:00": 114,
        "2022-12-19T13:00:00": 132,
        "2022-12-20T08:14:00": 0,
        "2022-12-20T11:00:00": 453,        
        "2022-12-20T15:44:00": 0
        }
        """;    
    return json;
}

Using a Dictionary<DateTime, int> is the starting point

Dictionary<DateTime, int> wattsDict =
              JsonSerializer.Deserialize<Dictionary<DateTime, int>>(GetWattsJson());

to later copy the values into the type Watt

public class Watt
{   
    public int Counter {get; set;}
    public DateTime Date { get; set; }
    public int Quantity { get; set; }
}

The copying is quite easy

List<Watt> wattList = new List<Watt>();     
int i = 0;
foreach (var (key, value) in wattsDict)
{
   wattList.Add(new Watt{Counter = i, Date = key, Quantity = value});    
   i++;
}

Result in linqpad

Convert Date

This code show how to change the date format

• datetimeformatinfo
• cultureinfo

string timeString = "2022-12-19 08:14:00";  
var dateVal = DateTime.ParseExact(timeString
                  , "yyyy-MM-dd HH:mm:ss"
                  , CultureInfo.InvariantCulture);      
string output1 = dateVal.ToString("s"); // 2022-12-19T08:14:00