https://stackoverflow.com/questions/62663702 | C# Online Compiler

https://stackoverflow.com/questions/62663702 by Brian Rogers

using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using Newtonsoft.Json;
using Newtonsoft.Json.Linq;
					
public class Program
{
	public static void Main()
	{
        string json = @"
            [
                [""John"", 30, ""BMW""],
                [""Tim"", 45, ""Ford""],
                [""Kim"", 34, ""Toyota""]
            ]";
		
		var items = JsonConvert.DeserializeObject<IEnumerable<Person>>(json);
		
		foreach (var item in items)
		{
			Console.WriteLine(item.Name + ", age " + item.Age + ", drives a " + item.Car + ".");
		}
	}
}

[JsonConverter(typeof(ArrayToObjectConverter<Person>))]
public class Person 
{
    [JsonArrayIndex(0)]
    public string Name { get; set; }
	
    [JsonArrayIndex(1)]
    public int Age { get; set; }
	
    [JsonArrayIndex(2)]
    public string Car { get; set; }
}

public class JsonArrayIndexAttribute : Attribute
{
    public int Index { get; private set; }
    public JsonArrayIndexAttribute(int index)
    {
        Index = index;
    }
}

public class ArrayToObjectConverter<T> : JsonConverter where T : class, new()
{
    public override bool CanConvert(Type objectType)
    {
        return objectType == typeof(T);
    }

    public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
    {
        JArray array = JArray.Load(reader);

        var propsByIndex = typeof(T).GetProperties()
            .Where(p => p.CanRead && p.CanWrite && p.GetCustomAttribute<JsonArrayIndexAttribute>() != null)
            .ToDictionary(p => p.GetCustomAttribute<JsonArrayIndexAttribute>().Index);

        JObject obj = new JObject(array
            .Select((jt, i) =>
            {
                PropertyInfo prop;
                return propsByIndex.TryGetValue(i, out prop) ? new JProperty(prop.Name, jt) : null;
            })
            .Where(jp => jp != null)
        );

        T target = new T();
        serializer.Populate(obj.CreateReader(), target);

        return target;
    }

    public override bool CanWrite
    {
        get { return false; }
    }

    public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
    {
        throw new NotImplementedException();
    }
}

​x
 
using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using Newtonsoft.Json;
using Newtonsoft.Json.Linq;
                    
public class Program
{
    public static void Main()
    {
        string json = @"
            [
                [""John"", 30, ""BMW""],
                [""Tim"", 45, ""Ford""],
                [""Kim"", 34, ""Toyota""]
            ]";
        
        var items = JsonConvert.DeserializeObject<IEnumerable<Person>>(json);
        
        foreach (var item in items)
        {
            Console.WriteLine(item.Name + ", age " + item.Age + ", drives a " + item.Car + ".");
        }
    }
}
​
[JsonConverter(typeof(ArrayToObjectConverter<Person>))]
public class Person 
{
    [JsonArrayIndex(0)]
    public string Name { get; set; }
    
    [JsonArrayIndex(1)]
    public int Age { get; set; }
    
    [JsonArrayIndex(2)]
    public string Car { get; set; }
}
​
public class JsonArrayIndexAttribute : Attribute
{
    public int Index { get; private set; }
    public JsonArrayIndexAttribute(int index)
    {
        Index = index;
    }
}
​
public class ArrayToObjectConverter<T> : JsonConverter where T : class, new()
{
    public override bool CanConvert(Type objectType)
    {
        return objectType == typeof(T);
    }
​
    public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
    {
        JArray array = JArray.Load(reader);
​
        var propsByIndex = typeof(T).GetProperties()
            .Where(p => p.CanRead && p.CanWrite && p.GetCustomAttribute<JsonArrayIndexAttribute>() != null)
            .ToDictionary(p => p.GetCustomAttribute<JsonArrayIndexAttribute>().Index);
​
        JObject obj = new JObject(array
            .Select((jt, i) =>
            {
                PropertyInfo prop;
                return propsByIndex.TryGetValue(i, out prop) ? new JProperty(prop.Name, jt) : null;
            })
            .Where(jp => jp != null)
        );
​
        T target = new T();
        serializer.Populate(obj.CreateReader(), target);
​
        return target;
    }
​
    public override bool CanWrite
    {
        get { return false; }
    }
​
    public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
    {
        throw new NotImplementedException();
    }
}

Compilation error (line 1, col 0): Labels are not valid outside methods/multiline lambdas.
Compilation error (line 1, col 0): Syntax error.
Compilation error (line 2, col 0): Labels are not valid outside methods/multiline lambdas.
Compilation error (line 2, col 0): Syntax error.
Compilation error (line 3, col 0): Labels are not valid outside methods/multiline lambdas.
Compilation error (line 3, col 0): Syntax error.
Compilation error (line 4, col 0): Labels are not valid outside methods/multiline lambdas.
Compilation error (line 4, col 0): Syntax error.
Compilation error (line 5, col 0): Labels are not valid outside methods/multiline lambdas.
Compilation error (line 5, col 0): Syntax error.
Compilation error (line 6, col 0): Labels are not valid outside methods/multiline lambdas.
Compilation error (line 6, col 0): Syntax error.
Compilation error (line 7, col 0): Labels are not valid outside methods/multiline lambdas.
Compilation error (line 7, col 0): Syntax error.
Compilation error (line 8, col 0): Labels are not valid outside methods/multiline lambdas.
Compilation error (line 8, col 0): Syntax error.
Compilation error (line 9, col 0): Labels are not valid outside methods/multiline lambdas.
Compilation error (line 9, col 0): Syntax error.
Compilation error (line 10, col 0): Labels are not valid outside methods/multiline lambdas.
Compilation error (line 10, col 0): Syntax error.
Compilation error (line 11, col 0): Labels are not valid outside methods/multiline lambdas.
Compilation error (line 11, col 0): Syntax error.
Compilation error (line 12, col 0): Labels are not valid outside methods/multiline lambdas.
Compilation error (line 12, col 0): Syntax error.
Compilation error (line 13, col 0): Labels are not valid outside methods/multiline lambdas.
Compilation error (line 13, col 0): Syntax error.
Compilation error (line 14, col 0): Labels are not valid outside methods/multiline lambdas.
Compilation error (line 14, col 0): Syntax error.
Compilation error (line 15, col 0): Labels are not valid outside methods/multiline lambdas.
Compilation error (line 15, col 0): Syntax error.
Compilation error (line 16, col 0): Labels are not valid outside methods/multiline lambdas.
Compilation error (line 16, col 0): Syntax error.
Compilation error (line 17, col 0): Labels are not valid outside methods/multiline lambdas.
Compilation error (line 17, col 0): Syntax error.
Compilation error (line 18, col 0): Labels are not valid outside methods/multiline lambdas.
Compilation error (line 18, col 0): Syntax error.
Compilation error (line 19, col 0): Labels are not valid outside methods/multiline lambdas.
Compilation error (line 19, col 0): Syntax error.
Compilation error (line 20, col 0): Labels are not valid outside methods/multiline lambdas.
Compilation error (line 20, col 0): Syntax error.
Compilation error (line 21, col 0): Labels are not valid outside methods/multiline lambdas.
Compilation error (line 21, col 0): Syntax error.
Compilation error (line 22, col 0): Labels are not valid outside methods/multiline lambdas.
Compilation error (line 22, col 0): Syntax error.
Compilation error (line 23, col 0): Labels are not valid outside methods/multiline lambdas.
Compilation error (line 23, col 0): Syntax error.
Compilation error (line 24, col 0): Labels are not valid outside methods/multiline lambdas.
Compilation error (line 24, col 0): Syntax error.
Compilation error (line 25, col 0): Labels are not valid outside methods/multiline lambdas.
Compilation error (line 25, col 0): Syntax error.

Last Run:	5:51:01 am
Compile:	0s
Execute:	0.157s
Memory:	0b
CPU:	0s

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