C#•3y ago

Newtonsoft.Json Serialization Exception

Trying to deserialize a List<Highscore> for my project and it throws this exception: Unhandled exception. Newtonsoft.Json.JsonSerializationException: Error converting value "{"Name":"Willy","Time":316}" to type 'ReactionGame.Highscore' Code (T is List<Highscore>):

    public virtual async Task<T> Get<T>(string url) where T : class
    {
        using var client = new HttpClient();

        var stringResult = await client.GetStringAsync(url);
        return JsonConvert.DeserializeObject<T>(stringResult, new JsonSerializerSettings{NullValueHandling = NullValueHandling.Ignore});
    }

    public virtual async Task<T> Get<T>(string url) where T : class
    {
        using var client = new HttpClient();

        var stringResult = await client.GetStringAsync(url);
        return JsonConvert.DeserializeObject<T>(stringResult, new JsonSerializerSettings{NullValueHandling = NullValueHandling.Ignore});
    }

Model:

namespace ReactionGame
{
    public class Highscore
    {
        [JsonProperty]
        public string Name { get; set; }
        [JsonProperty]
        public long Time { get; set; }

        public override string ToString()
        {
            return Name + "  -  " + Time;
        }

        [JsonConstructor]
        public Highscore(string name, long time)
        {
            Name = name;
            Time = time;
        }
    }
}

namespace ReactionGame
{
    public class Highscore
    {
        [JsonProperty]
        public string Name { get; set; }
        [JsonProperty]
        public long Time { get; set; }

        public override string ToString()
        {
            return Name + "  -  " + Time;
        }

        [JsonConstructor]
        public Highscore(string name, long time)
        {
            Name = name;
            Time = time;
        }
    }
}

Anyone know what might be wrong? I'm at a loss.

26 Replies

MODiX•3y ago

Ero#1111

REPL Result: Success

using Newtonsoft.Json;

var json = """
{
  "Name": "Willy",
  "Time": 316
}
""";

var hs = JsonConvert.DeserializeObject<Highscore>(json, new JsonSerializerSettings
{
  NullValueHandling = NullValueHandling.Ignore
});

Console.WriteLine(hs);

class Highscore
{
[JsonProperty]
public string Name { get; set; }
[JsonProperty]
public long Time { get; set; }

public override string ToString()
{
  return Name + "  -  " + Time;
}

[JsonConstructor]
public Highscore(string name, long time)
{
  Name = name;
  Time = time;
}
}

using Newtonsoft.Json;

var json = """
{
  "Name": "Willy",
  "Time": 316
}
""";

var hs = JsonConvert.DeserializeObject<Highscore>(json, new JsonSerializerSettings
{
  NullValueHandling = NullValueHandling.Ignore
});

Console.WriteLine(hs);

class Highscore
{
[JsonProperty]
public string Name { get; set; }
[JsonProperty]
public long Time { get; set; }

public override string ToString()
{
  return Name + "  -  " + Time;
}

[JsonConstructor]
public Highscore(string name, long time)
{
  Name = name;
  Time = time;
}
}

Console Output

Willy  -  316

Willy  -  316

Compile: 692.423ms | Execution: 158.707ms | React with ❌ to remove this embed.

ero•3y ago

¯\_(ツ)_/¯

𝔉𝔩𝔢𝔢𝔠𝔢OP•3y ago

Thanks xD What did you change exactly?

ero•3y ago

Nothing Just showing your that it should work

𝔉𝔩𝔢𝔢𝔠𝔢OP•3y ago

Bruh 😓 thanks anyways :)

MODiX•3y ago

Check your private messages, @𝕭𝖔𝖙𝖙𝖑𝖊_𝕭𝖆𝖗𝖔𝖓.

MODiX•3y ago

Ero#1111

REPL Result: Success

using Newtonsoft.Json;

var json = """
[
{
  "Name": "Willy",
  "Time": 316
},
{
  "Name": "Willy",
  "Time": 316
}
]
""";

var hs = JsonConvert.DeserializeObject<List<Highscore>>(json, new JsonSerializerSettings
{
  NullValueHandling = NullValueHandling.Ignore
});

Console.WriteLine(hs[0]);

class Highscore
{
[JsonProperty]
public string Name { get; set; }
[JsonProperty]
public long Time { get; set; }

public override string ToString()
{
  return Name + "  -  " + Time;
}

[JsonConstructor]
public Highscore(string name, long time)
{
  Name = name;
  Time = time;
}
}

using Newtonsoft.Json;

var json = """
[
{
  "Name": "Willy",
  "Time": 316
},
{
  "Name": "Willy",
  "Time": 316
}
]
""";

var hs = JsonConvert.DeserializeObject<List<Highscore>>(json, new JsonSerializerSettings
{
  NullValueHandling = NullValueHandling.Ignore
});

Console.WriteLine(hs[0]);

class Highscore
{
[JsonProperty]
public string Name { get; set; }
[JsonProperty]
public long Time { get; set; }

public override string ToString()
{
  return Name + "  -  " + Time;
}

[JsonConstructor]
public Highscore(string name, long time)
{
  Name = name;
  Time = time;
}
}

Console Output

Willy  -  316

Willy  -  316

Compile: 742.622ms | Execution: 179.356ms | React with ❌ to remove this embed.

ero•3y ago

Still works for a list too

𝔉𝔩𝔢𝔢𝔠𝔢OP•3y ago

Hm Might have found it Seems the json string has been altered somehow

["{\"Name\":\"Pet\",\"Time\":316}","{\"Name\":\"Pet\",\"Time\":278}"]

["{\"Name\":\"Pet\",\"Time\":316}","{\"Name\":\"Pet\",\"Time\":278}"]

ero•3y ago

where are you getting this input?

𝔉𝔩𝔢𝔢𝔠𝔢OP•3y ago

Im sending the data from my game to a web api then using the get method to retrieve it from the site

ero•3y ago

is the web api strictly a middleman for this or does it do more?

𝔉𝔩𝔢𝔢𝔠𝔢OP•3y ago

No it is just supposed to store data

ero•3y ago

then why not just send the data from the game directly to the app?

𝔉𝔩𝔢𝔢𝔠𝔢OP•3y ago

That is what i am attempting using the post and get endpoints

ero•3y ago

well no, that's a middleman

𝔉𝔩𝔢𝔢𝔠𝔢OP•3y ago

this is what the repo looks like roughly

𝔉𝔩𝔢𝔢𝔠𝔢OP•3y ago

The WebApi parts job is to take the data sent from the reactiongame and store it into a SQLite database The get method should then get that data and return it to the game

ero•3y ago

right well, anyway. that seems like incorrectly formatted json there shouldn't be quotes after [ and before ]

𝔉𝔩𝔢𝔢𝔠𝔢OP•3y ago

ait then i will look into this :)

Pobiega•3y ago

that looks like a List<string> where each string is a json serialized object

ero•3y ago

yup also consider using System.Text.Json instead of Newtonsoft

𝔉𝔩𝔢𝔢𝔠𝔢OP•3y ago

Yeah I'll try that Thanks ^^

ero•3y ago

it won't fix this! but it is still just. better in every way

MODiX•3y ago

Ero#1111

REPL Result: Success

using System.Text.Json;

var json = """
[
  {
    "Name": "Pet",
    "Time": 316
  },
  {
    "Name": "Pet",
    "Time": 278
  }
]
""";

var hs = JsonSerializer.Deserialize<List<Highscore>>(json);
Console.WriteLine(hs[0]);

record Highscore(
string Name,
int Time);

using System.Text.Json;

var json = """
[
  {
    "Name": "Pet",
    "Time": 316
  },
  {
    "Name": "Pet",
    "Time": 278
  }
]
""";

var hs = JsonSerializer.Deserialize<List<Highscore>>(json);
Console.WriteLine(hs[0]);

record Highscore(
string Name,
int Time);

Console Output

Highscore { Name = Pet, Time = 316 }

Highscore { Name = Pet, Time = 316 }

Compile: 753.600ms | Execution: 95.491ms | React with ❌ to remove this embed.

𝔉𝔩𝔢𝔢𝔠𝔢OP•3y ago

Yup

Gaming

Programming

Newtonsoft.Json Serialization Exception

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