Question

I searched the web but haven’t found a real good answer for this question..

Let’s say I have a form, on AddToList.aspx, and i want that after you hit send, it will direct you back to List.aspx, with a message “The Item was added to list” in a message box div.

do i need to send List.aspx?msg=my message, or is there another good way of doing it?

EDIT:

so i made this helper class:

   public class MessageHelper : System.Web.UI.MasterPage
    {
        public void SetMessage(String message)
        {
            Session["Message"] = message;
        }

        public string GetMessage()
        {
            if (String.IsNullOrEmpty(Session["Message"]))
            {
                String temp = Session["Message"];
                Session["Message"] = "";
                return temp;
            }
            else
            {
                return "";
            }
        }
    }

and got this error:

Error   32  The best overloaded method match for 'string.IsNullOrEmpty(string)' has some invalid arguments
Error   33  Argument '1': cannot convert from 'object' to 'string'
Error   34  Cannot implicitly convert type 'object' to 'string'. An explicit conversion exists (are you missing a cast?)

Answer 1

You could certainly use the query string to pass data to your List.aspx page, but be careful passing text that you’re planning on writing out in the HTML – you’ll need to protect against XSS attacks.

There are several other ways to do this. Chances are, you’re going to have several places in your application where you want to redirect the user to another page, but also display a message that has something to do with what they did on the previous page (saved an item, deleted an item, etc.). It would be better to come up with more of a global scheme for this rather than a one-off just for this particular instance.

One idea is to use the Session for storing a message, then do your redirect.

Session("Message") = "Item was added to list."
Response.Redirect("List.aspx")

Then, on your pages (or a Master Page, perhaps), you check Session("Message") and if it’s got something, you show that message to the user, then clear that variable.

If Session("Message") IsNot Nothing Then
  Response.Write(CType(Session("Message"), String)) 'or set a label text, or show a pop up div, or whatever'
  Session("Message") = Nothing
End If

If you use this approach, I recommend you write a helper class, and just use that to manage your messaging:

MessageHelper.SetMessage("Item added to list.")

and

MessageHelper.GetMessage()

would be the methods you would need.