Question

I’m looking for a way to use RedirectToAction while passing along the current request’s GET parameters.

So upon going to:
http://mydomain.com/MyController/MyRedirectAction?somevalue=1234

I would then want to redirect and persist somevalue with the a redirect without having to explicitly build a route dictionary and explicitly setting somevalue

public ActionResult MyRedirectAction()
{
    if (SomeCondition) 
        RedirectToAction("MyAction", "Home");
}

The redirected action could then use somevalue if available:

public ActionResult MyAction()
{
    string someValue = Request.QueryString["somevalue"];
}

Is there a clean way to do this?

Answer 1

A custom action result could do the job:

public class MyRedirectResult : ActionResult
{
    private readonly string _actionName;
    private readonly string _controllerName;
    private readonly RouteValueDictionary _routeValues;

    public MyRedirectResult(string actionName, string controllerName, RouteValueDictionary routeValues)
    {
        _actionName = actionName;
        _controllerName = controllerName;
        _routeValues = routeValues;
    }

    public override void ExecuteResult(ControllerContext context)
    {
        var requestUrl = context.HttpContext.Request.Url;
        var url = UrlHelper.GenerateUrl(
            "", 
            _actionName, 
            _controllerName, 
            requestUrl.Scheme,
            requestUrl.Host,
            null,
            _routeValues, 
            RouteTable.Routes, 
            context.RequestContext, 
            false
        );
        var builder = new UriBuilder(url);
        builder.Query = HttpUtility.ParseQueryString(requestUrl.Query).ToString();
        context.HttpContext.Response.Redirect(builder.ToString(), false);
    }
}

and then:

public ActionResult MyRedirectAction()
{
    return new MyRedirectResult("MyAction", "Home", null);
}