Clear or Remove query string in ASP.Net

Question

I have a QueryString named 'flagEdit' and I want to remove it after fetching it's value. But when i try to remove it using

Request.QueryString.Clear(); 

or

Request.QueryString.Remove("editFlag"); 

This error occurs -

System.NotSupportedException: Collection is read-only.

So, I want to know how to remove query string after fetches it's value

Answer 1

Removing (Deleting) Querystring in ASP.NET

Request.QueryString.Remove("editFlag") 

If you do the above, you will get an error

collection is read-only.

So, we need to write the below code before deleting the query string.

Try this way

PropertyInfo isreadonly =    typeof(System.Collections.Specialized.NameValueCollection).GetProperty(   "IsReadOnly", BindingFlags.Instance | BindingFlags.NonPublic); // make collection editable isreadonly.SetValue(this.Request.QueryString, false, null); // remove this.Request.QueryString.Remove("editFlag"); 

You can also try this way

    var nvc = HttpUtility.ParseQueryString(Request.Url.Query);     nvc.Remove("editFlag");     string url = Request.Url.AbsolutePath + "?" + nvc.ToString();      Response.Redirect(url); 

Hope this helps

Answer 2

If you are concerned about future page postbacks running the same code you intended to run when querystring has a value, simply add a if(!Page.IsPostBack) condition.