Page Error event

bmains · January 14th, 2004, 01:27 PM

Hello,

I'm a little unfamiliar with the page error event. Does the error event execute when an error occurs outside of a try..catch statement? Does it catch any error regardless of the try..catch event? Do you have to explicitly raise an error with the page object or something of that nature?

Thanks,

Brian Mains

planoie · January 14th, 2004, 01:44 PM

What Page Error event are you referring to? That doesn't ring a bell.

Peter
------------------------------------------------------
Work smarter, not harder.

bmains · January 14th, 2004, 05:43 PM

This is the definition from VS.NET:

Private Sub Page_Error(ByVal sender As Object, ByVal e As System.EventArgs) Handles
MyBase.Error

End Sub

stu9820 · January 14th, 2004, 05:49 PM

It catches and handles any error that occurs in a page and is executed whenever an unhandled exception occurs. You must include Server.ClearError() otherwise the default error generated by the ASP.NET framework would be displayed.

Private Sub Page_Error(ByVal sender As Object, ByVal e As System.EventArgs) Handles MyBase.Error
Response.write(Server.GetLastError.Message)
Server.ClearError()
End Sub

bmains · January 15th, 2004, 10:38 AM

I'm trying to test this process, and I have the following code:

Code:

Private Sub Page_Error(ByVal sender As Object, ByVal e As System.EventArgs) Handles MyBase.Error
    Label1.Text = "Error:  " & Server.GetLastError.Message
    Label1.Visible = True
    Server.ClearError()
End Sub

Private Sub LinkButton1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles LinkButton1.Click
    Throw New System.Exception("Error occurred")
End Sub

When the link button is clicked, it throws an exception. The page error event catches the error, sets the label to the message of the error and sets the visible property to true, and clears the error. However, the result is a blank page! The html for this page is:

Code:

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD>
<META http-equiv=Content-Type content="text/html; charset=windows-1252"></HEAD>
<BODY></BODY></HTML>

Why is this happening?

Thanks.

planoie · January 15th, 2004, 10:46 AM

Code the server be transferring you to the generic error handling page, but because the error is cleared, it has nothing to show?

Peter
------------------------------------------------------
Work smarter, not harder.

stu9820 · January 15th, 2004, 11:13 AM

You can try this:

Set <customErrors mode="On" /> in the web.config file.
Then at the top of your page add a page directive like this:
<%@ Page ErrorPage="errorpage.aspx" %>

And give a nice user friendly message stating that there was an error while processing your request.

bmains · January 15th, 2004, 04:26 PM

I think I will use the web config file to display custom errors. It just seems strange that you can't use the Page error event to trap it also.

Thanks.

stu9820 · January 15th, 2004, 04:42 PM

I got both to work for me although not at the same time.

I do prefer the custom errors page because you can simply say "Site is temporarily down. Please return later". And have the error emailed to you from the global.asax file (application_error).

stu9820 · January 16th, 2004, 10:49 AM

Here is a good article about errors in ASP.NET.

http://www.15seconds.com/issue/030102.htm