具有用户名的模型绑定Asp.Net Core

Question

Currently I have a generic method in my Web API that takes in a collection and stores it into the database. I'm adding the username by looping through the entire collection again and adding the username.

I feel like this is inefficient and I would like to write something generic so that I can add the username at the time of model binding or when I'm using automapper. I wonder if there is a more efficient way to do this, than my current approach:

[HttpPost("collections")]
public async virtual Task<IActionResult> PostCollection([FromBody] IEnumerable<DtoPostType> dtoCollection)
{
    try
    {
        var principal = HttpContext.User.Identity as ClaimsIdentity;
        var entitiesToSave = _mapper.Map<List<T>>(dtoCollection);


        foreach (T item in entitiesToSave)
        {
            if (ModelState.IsValid)
            {
                item.CreatedUser = principal.Name;
                _repo.Create<T>(item);

            }
            else
            {
                return BadRequest(ModelState);
            }
        }

        await _repo.SaveAsync();

        return Ok();
    }

    catch (Exception exp)
    {
        _logger.LogCritical($"There was an issue with mapping for {exp}");
        return BadRequest(exp);
    }
}

Answer 1

AutoMapper does have support for defining mapping actions in ASP.NET Core . You could likely configure that as shown there and use something like the following for the Process method of the IMappingAction<> implementation:

public void Process(DtoPostType source, EntityType destination)
{
    destination.CreatedUser = 
        (_httpContextAccessor.HttpContext.User.Identity as ClaimsIdentity)?.Name;
}

I'd caution that this might be premature optimization though. This is a nice solution for ensuring that something happens consistently on every map in the same way. But it may also serve to make the code less readable to someone coming later on, so just be aware of that.