How to not send headers to the browser for application errors before handling errors

Question

Right now i am able to generate custom errors page with the code below at web config

<customErrors mode="On" defaultRedirect="Error404.aspx" redirectMode="ResponseRewrite">
  <error statusCode="404" redirect="~/Error404.aspx"/>
</customErrors>

This catches all non existing pages as long as they are not aspx

example : http://www.monstermmorpg.com/StackOverflow

Now if you make it this way

http://www.monstermmorpg.com/StackOverflow.aspx

the global asax is catching error

void Application_Error(object sender, EventArgs e)
{
    // Code that runs when an unhandled error occurs
    if (Server.GetLastError() != null)
        if (Server.GetLastError().GetBaseException() != null)
        {
            Exception objErr = Server.GetLastError().GetBaseException();
            ErrorLogger.LogError(Request.Url.ToString(), objErr.Message.ToString(), objErr.StackTrace.ToString());
            if (objErr.Message.IndexOf("does not exist") != -1)
            {

                // Response.Redirect("http://www.monstermmorpg.com");

            }
        }
}

But at here it tells browser that the page you want to visit exists. Actually it is not exists. So i want to tell browser that the page you are looking for is 404.

How can i do that =?

If i redirect in global asax to the error404.aspx page, it gives me error that headers already sent

here error

Answer 1

Good day

You will want to try the following

Global 301 redirection from domain to www.domain

Response.Status = "301 Moved Permanently";   
Response.AddHeader("Location",   "http://"+host+port+"/404.aspx");
Response.End();