I have a controller action, that accepts an object from the query parameters:

/// <summary>
Get a paginated list with filters.
</summary>
HttpGet]
Route("")]
public virtual async Task<ActionResult<PagedList<ViewType>>> GetMultiple([FromQuery] SearchParametersType parameters)
{
    var entities = await _repository.GetMultiple(parameters);
    SetPaginationHeaders(entities);
    return Ok(_mapper.Map<IEnumerable<ViewType>>(entities).ShapeData(parameters.Fields));
}

In my example the SearchParametersType looks like this:

public class MovieGenreRelationSearchParameters : SearchParameters
{
    [TypeConverter(typeof(ListOfGuidConverter))]
    public List<Guid>? MovieIds { get; set; } = new List<Guid>();

    [TypeConverter(typeof(ListOfGuidConverter))]
    public List<Guid>? GenreIds { get; set; } = new List<Guid>();
}

The payload from the frontend instead sends a comma separated list like this:

/movies/moviegenrerelation?movieIds=08dc7544-985e-4a84-8001-82cdd24bc05c,08dc7542-c799-4f40-80c2-e04d7a1251ac

So I wrote a TypeConverter that converts a comma separated list of strings from a string into a list of Guids which looks like this:

public class ListOfGuidConverter : TypeConverter
{
    public override bool CanConvertFrom(ITypeDescriptorContext? context, Type sourceType)
    {
        return sourceType == typeof(string);
    }

    public override object ConvertFrom(ITypeDescriptorContext? context, CultureInfo? culture, object value)
    {
        if (value == null) return new List<Guid>();
        var guidsRaw = (value as string).Split(',');
        return (from guidRaw in guidsRaw select new Guid(guidRaw)).ToList();
    }
}

My problem is, that the type converter isn’t used at all. Somebody may know what I am doing wrong?

Thanks for any help 🙂

The TypeConverter is used.