using System;

using System.Collections.Generic;

using System.Collections;

using System.Reflection;

using System.Text.Json;

​

public static class AppExtensions

{

    public static T PatchFrom<T>(this T updateModel, Dictionary<string, object> patchModel)

    {

        var keysToUpdate = new List<string>(patchModel.Keys);

        foreach (var key in keysToUpdate) 

        {

            var parentType = updateModel.GetType();

            var keyProperty = parentType.GetProperty(key, BindingFlags.IgnoreCase |  BindingFlags.Public | BindingFlags.Instance);

            var keyType = keyProperty.GetType();

            updateModel.GetType().GetProperty(key, BindingFlags.IgnoreCase |  BindingFlags.Public | BindingFlags.Instance).SetValue(updateModel, patchModel[key], null);

        }

        return updateModel;

    }

}

​

public class TestEntity

{

    public string A { get; set; }

    public int B { get; set; }

}

​

public class PatchableModel

{

}

​

public class UpdateTestModel

{

    public string A { get; set; }

    public int B { get; set; }

    public List<int> C { get; set; }

}

​

public class Program

{

    public static void Main()

    {

        var patchPayload = new Dictionary<string, object>() { {"b", 2} }; // Only Specified "B"

        var existingEntity = new TestEntity { A = "Test", B = 2 }; // Value from DB

        var patchedEntity = existingEntity.PatchFrom(patchPayload); // Set only specified values to entity

        Console.WriteLine(JsonSerializer.Serialize(patchedEntity)); // Result

    }

}