title: Return a list of error messages with 400 Bad Request response in Web API 2
body: <p>How can I return a list of error messages from Web Api 2 with 400 Bad Request status code? See the example below. Usually I use BadRequest method to return the 400 status code but it doesn't have any overload where it accepts a collection of string. It has an overload where it accepts ModelStateDisctionary. Does it mean I will have to create ModelStateDictionary from a list of error messages? </p>
  
  <pre><code>[Route("")]
  [HttpPost]
  public IHttpActionResult Add(Object data)
  {
      var valid = _serviceLayer.Validate(data);
      if(!valid) 
      {
          var errors = valid.Errors;
          // errors is an array of string 
          // How do I return errors with Bad Request status code here? 
      }
      var updatedObject = _serviceLayer.Save(data);
      return Ok(updatedObject);
  }
  </code></pre>