Using System.Text.Json for Camel Case Serialization

Use JsonPropertyName Attribute for Camel Case Serialization

public class PersonWithAttributes
{
    [JsonPropertyName("firstName")]
    public string? FirstName { get; set; }
    
    [JsonPropertyName("surname")]
    public string? Surname { get; set; }
    
    [JsonPropertyName("age")]
    public int? Age { get; set; }
    
    [JsonPropertyName("isActive")]
    public bool? IsActive { get; set; }
}

Create JsonSerializerExtensions

public static class JsonSerializerExtensions
{
    public static string SerializeWithCamelCase<T>(this T data)
    {
        return JsonSerializer.Serialize(data, new JsonSerializerOptions
        {
            PropertyNamingPolicy = JsonNamingPolicy.CamelCase
        });
    }

    public static T DeserializeFromCamelCase<T>(this string json)
    {
        return JsonSerializer.Deserialize<T>(json, new JsonSerializerOptions
        {
            PropertyNamingPolicy = JsonNamingPolicy.CamelCase
        });
    }
}

How to use ?

var personWithAttributes = new PersonWithAttributes
{
    Age = 20,
    FirstName = "John",
    Surname = "Doe",
    IsActive = true
};

JsonSerializer.Serialize(personWithAttributes, new JsonSerializerOptions
{
    PropertyNamingPolicy = JsonNamingPolicy.CamelCase
});

or

personWithAttributes.SerializeWithCamelCase();

or

personWithAttributes.DeserializeFromCamelCase<PersonWithAttributes>()