Query string param is missed when form validation fail

Question

I have an form with following url: CreateEntity?officeCodeId=5

When I send form to validate and if validation is fail it returns just CreateEntity u

Answer 1

Your final answer is excellent and works great, although you can further enhance it to make it more generic by simply including Request.QueryString:

Then use the POST action:

[HttpPost]
protected virtual ActionResult CreateEntity(TEditViewModel model)
{
    if (!ModelState.IsValid)
    {
        return View(model);
    }