Swashbuckle与.NET Core：错误时如何返回空响应体？

我正在创建如下接口：

/// <summary>
/// Starts a new validation process
/// </summary>
/// <param name="order"></param>
/// <response code="201">Campaing created successfully</response>
/// <response code="400">An invalid request has been made. Check response for details.</response>
/// <response code="406">A campaing is already in progress for this target for this requestor</response> 
[HttpPut]
[Produces("application/json")]
[ProducesResponseType(StatusCodes.Status201Created, Type = typeof(ValidationProcessBase))]
[ProducesResponseType(StatusCodes.Status400BadRequest, Type = typeof(IEnumerable<string>))]
[ProducesResponseType(StatusCodes.Status406NotAcceptable)]
public async Task StartNewProcess([FromBody] StartValidationProcessOrder order)
{
    //return null;
}

我希望406响应的响应体为空（类似204响应），但当前返回的是ProblemDetails格式，请问如何实现？

ASP.NET Core默认会将错误状态码包装为ProblemDetails格式，要让406返回空响应体，可按以下步骤调整：

1. 修改接口返回类型
   将方法返回类型从Task改为Task<IActionResult>，这样可以灵活返回不同类型的响应结果。

2. 手动返回406状态码（无响应体）
   在触发406的业务逻辑分支中，直接返回StatusCodeResult，不要抛出异常（抛出异常会被框架自动包装为ProblemDetails）。

更新后的接口代码示例：

/// <summary>
/// Starts a new validation process
/// </summary>
/// <param name="order"></param>
/// <response code="201">Campaing created successfully</response>
/// <response code="400">An invalid request has been made. Check response for details.</response>
/// <response code="406">A campaing is already in progress for this target for this requestor</response> 
[HttpPut]
[Produces("application/json")]
[ProducesResponseType(StatusCodes.Status201Created, Type = typeof(ValidationProcessBase))]
[ProducesResponseType(StatusCodes.Status400BadRequest, Type = typeof(IEnumerable<string>))]
[ProducesResponseType(StatusCodes.Status406NotAcceptable)]
public async Task<IActionResult> StartNewProcess([FromBody] StartValidationProcessOrder order)
{
    // 示例：判断是否已有进行中的流程
    bool isProcessInProgress = await CheckIfProcessIsInProgressAsync(order);
    
    if (isProcessInProgress)
    {
        // 返回406状态码，无响应体
        return new StatusCodeResult(StatusCodes.Status406NotAcceptable);
    }

    // 正常流程：创建验证流程并返回201
    var validationResult = await _validationService.CreateProcessAsync(order);
    return CreatedAtAction(nameof(GetProcess), new { id = validationResult.Id }, validationResult);
}

3. 保留Swagger注解
   原有的[ProducesResponseType(StatusCodes.Status406NotAcceptable)]注解无需修改，它会在Swagger文档中正确标识该状态码无响应体。

内容的提问来源于stack exchange，提问作者Leonardo