ASP.NET: how to get a reference to page "B" from page "A" codebehind?

Question

I'm trying to call ScriptManager.RegisterStartupScript from page "A" so that when page "B" loads it displays an alert, but can't figure out how to get a reference to page "B" to satisfy the Control argument in the method call.

I figure there's got to be something similar to Page.FindControl() that does this, but I'm stuck...

Answer 1

Are you popping up page B in a new window with JavaScript?

If so you can access page A from B by using window.opener. You can use that to access some alert function (e.g. SendAlert(alert)) on page A. So on page B you can say window.opener.SendAlert("It opened");

Answer 2

If "B" will run the script, then "B" must call RegisterStartupScript. Typically you would do this in the Page_Load event of page "B".

Answer 3

Register the startup script in page B. If you need to generate the script in page A, pass it to page B using one of the standard web mechanisms for persistence between pages ie querystring, hidden field, cookie , session variable, database. Normal caveats apply to each of those methods.