将JSON序列化为对象。 有些属性总是一样，有些则不同

Question

I am trying to build a function where a user can upload a json file.

Each row in the json file can have a different nr of properties(ie columns). 5 of these properties are always the same so I want those to be deserialized to an object. The rest of the properties have to go into a dictionary or something.

Here is a json example:

[{
        "Projekt": "Bakker Bouw Service",
        "Ruimte": "Hoofdgebouw",
        "Apparaat": {
            "project": "Bosboom001",
            "versie": "812"
        },
        "Apparaat naam": "",
        "Status": "Goedgekeurd",
        "Testname1": "",
        "Testname3": "2000-01-04T10:37:00+01:00",
        "Testname7": "2001-01-03T00:00:00+01:00"
    }, {
        "Projekt": "Bakker Bouw Service",
        "Ruimte": "Hoofdgebouw",
        "Apparaat": {
            "project": "Vlaams003",
            "versie": "713"
        },
        "Apparaat naam": "",
        "Status": "Goedgekeurd",
        "Testname1": "Slecht",
        "Testname7": "2000-01-04T10:37:00+01:00",
        "Testname9": "2001-01-03T00:00:00+01:00",
        "Testname16": "18MOhm",
        "Testname23": "OK"
    }, {
        "Projekt": "Bakker Bouw Service",
        "Ruimte": "Hoofdgebouw",
        "Apparaat": {
            "project": "Vlaams017",
            "versie": "73"
        },
        "Apparaat naam": "GDR34Z5",
        "Status": "Afgekeurd",
        "Testname7": "2000-01-04T10:37:00+01:00",
        "Testname10": "0,012mA",
        "Testname16": "200MOhm",
        "Testname23": "200MOhm",
        "Testname25": "Afgekeurd",
        "Testname31": "0,01mA"
    }
]

Here is the class to deserialze to:

public class KeuringRegel
{
    public string Projekt { get; set; }
    public string Ruimte { get; set; }
    public Apparaat Apparaat { get; set; }
    [JsonProperty(PropertyName = "Apparaat naam")]
    public string Apparaatnaam { get; set; }
    public string Status { get; set; }
    public Dictionary<string, object> testNames { get; set; }
}

public class Apparaat
{
    public string project { get; set; }
    public string versie { get; set; }
}

And here is the controller

public IActionResult Upload(IFormFile file)
    {
        string fileContent = null;
        using (var reader = new StreamReader(file.OpenReadStream()))
        {
            fileContent = reader.ReadToEnd();
        }
        List<KeuringRegel> keuringRegelList = JsonConvert.DeserializeObject<List<KeuringRegel>>(fileContent);
        //More stuff here
    }

The json successfully deserializes but the testNames value is always null. I understand why, because there is no testNames property in the Json file. However, how do I achieve what I want? I am no Json expert.

Answer 1

One way you can do this, assuming that there is only testNameNNNN entries as supplemental values, is to use the JsonExtensionDataAttribute like this:

public class KeuringRegel
{
    public string Projekt { get; set; }
    public string Ruimte { get; set; }
    public Apparaat Apparaat { get; set; }
    [JsonProperty(PropertyName = "Apparaat naam")]
    public string Apparaatnaam { get; set; }
    public string Status { get; set; }
    [JsonExtensionData()]
    public Dictionary<string, object> testNames { get; set; }
}

This will give you the values whos don't fall into one of the other properties:

It's a bit of a "blunt instrument" but you could always perform some post-processing on the returned instances of KeuringRegel to remove any errant entries from testNames (ie things that don't match the pattern testNameNNNN ).

If your JSON does contain things that don't match the pattern testNameNNNN which would therefore get included, you could implement a custom class for the testNames property:

public class KeuringRegel
{
    public string Projekt { get; set; }
    public string Ruimte { get; set; }
    public Apparaat Apparaat { get; set; }
    [JsonProperty(PropertyName = "Apparaat naam")]
    public string Apparaatnaam { get; set; }
    public string Status { get; set; }
    [JsonExtensionData()]
    public TestNames testNames { get; set; }
}

public class TestNames : Dictionary<string, object>
{
    public new void Add(string key, object value)
    {
        if (key.StartsWith("testname", StringComparison.OrdinalIgnoreCase))
        {
            base.Add(key, value);
        }
    }
}

This will check each item that is added to the testNames dictionary and prevent its addition if (as in my comment where I had an item in the JSON of "badgerBadgetCatCat": 3 ) it doesn't match the pattern.

Answer 2

Here u are full example

internal class Program
    {
        private static void Main(string[] args)
        {
            var str = @"[{
        ""Projekt"": ""Bakker Bouw Service"",
        ""Ruimte"": ""Hoofdgebouw"",
        ""Apparaat"": {
            ""project"": ""Bosboom001"",
            ""versie"": ""812""
        },
        ""Apparaat naam"": """",
        ""Status"": ""Goedgekeurd"",
        ""Testname1"": """",
        ""Testname3"": ""2000-01-04T10:37:00+01:00"",
        ""Testname7"": ""2001-01-03T00:00:00+01:00""
    }, {
        ""Projekt"": ""Bakker Bouw Service"",
        ""Ruimte"": ""Hoofdgebouw"",
        ""Apparaat"": {
            ""project"": ""Vlaams003"",
            ""versie"": ""713""
        },
        ""Apparaat naam"": """",
        ""Status"": ""Goedgekeurd"",
        ""Testname1"": ""Slecht"",
        ""Testname7"": ""2000-01-04T10:37:00+01:00"",
        ""Testname9"": ""2001-01-03T00:00:00+01:00"",
        ""Testname16"": ""18MOhm"",
        ""Testname23"": ""OK""
    }, {
        ""Projekt"": ""Bakker Bouw Service"",
        ""Ruimte"": ""Hoofdgebouw"",
        ""Apparaat"": {
            ""project"": ""Vlaams017"",
            ""versie"": ""73""
        },
        ""Apparaat naam"": ""GDR34Z5"",
        ""Status"": ""Afgekeurd"",
        ""Testname7"": ""2000-01-04T10:37:00+01:00"",
        ""Testname10"": ""0,012mA"",
        ""Testname16"": ""200MOhm"",
        ""Testname23"": ""200MOhm"",
        ""Testname25"": ""Afgekeurd"",
        ""Testname31"": ""0,01mA""
    }
]";

            var sw = Stopwatch.StartNew();

            var result = Mapper.Map(str);


            sw.Stop();
            Console.WriteLine($"Deserialized at {sw.ElapsedMilliseconds} ms ({sw.ElapsedTicks} tiks)");
        }

        public static class Mapper
        {
            static Mapper()
            {
                List<string> names = new List<string>();
                IEnumerable<PropertyInfo> p = typeof(KeuringRegel).GetProperties().Where(c => c.CanRead && c.CanWrite);
                foreach (var propertyInfo in p)
                {
                    var attr = propertyInfo.GetCustomAttribute<JsonPropertyAttribute>();
                    names.Add(attr != null ? attr.PropertyName : propertyInfo.Name);
                }

                Properties = names.ToArray();
            }


            private static string[] Properties { get; }



            public static KeuringRegel[] Map(string str)
            {
                var keuringRegels = JsonConvert.DeserializeObject<KeuringRegel[]>(str);
                var objs = JsonConvert.DeserializeObject(str) as IEnumerable;
                var objectList = new List<JObject>();
                foreach (JObject obj in objs)
                    objectList.Add(obj);

                for (var i = 0; i < keuringRegels.Length; i++)
                {
                    keuringRegels[i].testNames = new Dictionary<string, object>();
                    foreach (var p in objectList[i].Children().OfType<JProperty>().Where(c => !Properties.Contains(c.Name)).ToArray())
                        keuringRegels[i].testNames.Add(p.Name, p.Value);
                }

                return keuringRegels;
            }
        }


        public class KeuringRegel
        {
            public string Projekt { get; set; }
            public string Ruimte { get; set; }
            public Apparaat Apparaat { get; set; }

            [JsonProperty(PropertyName = "Apparaat naam")]
            public string Apparaatnaam { get; set; }

            public string Status { get; set; }
            public Dictionary<string, object> testNames { get; set; }
        }

        public class Apparaat
        {
            public string project { get; set; }
            public string versie { get; set; }
        }
    }