Add custom parameter into every query string using MVC action filter

Question

Basically I am try to add some custom query parameter into my all browser request using MVC action filter.

I am try to add action filter and write below code but getting error. like: NotSupportedException: Collection was of a fixed size.

public class CustomActionFilters : ActionFilterAttribute
{
    public override void OnActionExecuted(ActionExecutedContext filterContext)
    {
        filterContext.RouteData.Values.Keys.Add("customPara");

        filterContext.RouteData.Values.Values.Add("myAllcustomparamter");
                                  //OR
        filterContext.HttpContext.Request.Query.Keys.Add("customPara=myAllcustomparamter"); 
    }
}

So if I am write into url :http://localhost:15556/

than it will be http://localhost:15556?customPara=myAllcustomparamter

if open any other page like http://localhost:15556/image than it will be http://localhost:15556/image?customPara=myAllcustomparamter OR http://localhost:15556/image?inbuildparamter=anyvalue it will be http://localhost:15556/image?inbuildparamter=anyvalue&customPara=myAllcustomparamter

Answer 1

Finally got solution using redirect into action filter.

public class CustomActionFilters : ActionFilterAttribute
{
    public override void OnActionExecuted(ActionExecutedContext filterContext)
    {
        string longurl = HttpContext.Current.Request.Url.AbsoluteUri;
        var uriBuilder = new UriBuilder(longurl);
        var query = HttpUtility.ParseQueryString(uriBuilder.Query);
        var myAllcustomparamter = "myAllcustomparamterhere";
        query.Add("customPara", myAllcustomparamter);
        uriBuilder.Query = query.ToString();
        longurl = uriBuilder.ToString();
        if (!filterContext.HttpContext.Request.QueryString.HasValue || (filterContext.HttpContext.Request.QueryString.HasValue && !filterContext.HttpContext.Request.QueryString.Value.Contains("customPara")))
        {
            filterContext.Result = new RedirectResult(longurl);

        }                       
    }
}