title: Add custom parameter into every query string using MVC action filter
body: <p>Basically I am try to add some custom query parameter into my all browser request using MVC action filter.</p>
  
  <p>I am try to add action filter and write below code but getting error.
  like: NotSupportedException: Collection was of a fixed size.</p>
  
  <pre><code>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"); 
      }
  }
  </code></pre>
  
  <p>So if I am write into url :<a href="http://localhost:15556/" rel="nofollow noreferrer">http://localhost:15556/</a> </p>
  
  <p>than it will be <a href="http://localhost:15556?customPara=myAllcustomparamter" rel="nofollow noreferrer">http://localhost:15556?customPara=myAllcustomparamter</a></p>
  
  <p>if open any other page like <a href="http://localhost:15556/image" rel="nofollow noreferrer">http://localhost:15556/image</a>
  than it will be <a href="http://localhost:15556/image?customPara=myAllcustomparamter" rel="nofollow noreferrer">http://localhost:15556/image?customPara=myAllcustomparamter</a> OR
   <a href="http://localhost:15556/image?inbuildparamter=anyvalue" rel="nofollow noreferrer">http://localhost:15556/image?inbuildparamter=anyvalue</a> it will be  <a href="http://localhost:15556/image?inbuildparamter=anyvalue&amp;customPara=myAllcustomparamter" rel="nofollow noreferrer">http://localhost:15556/image?inbuildparamter=anyvalue&amp;customPara=myAllcustomparamter</a></p>