Emailing errors to yourself

The Code Dump ASP.NET Code Snips
1

Emailing errors to yourself

ASP.net in VB

If your site suffers a glitch it should

a) Redirect the user to a suitable error page which says Sorry, an error has occurred etc etc
b) Email the details of the error to your self for analysis

So, to redirect the user, put this code in your web.config file

<system.web>

 <!-- enable custom errors for the application -->
    <customErrors mode="RemoteOnly" defaultRedirect="ErrorPage.aspx"/>

etc etc

</system.web>

This “ErrorPage.aspx” will be in the root folder of your website. Any time an error occurs, including a 404 error, the user will be redirected to this error page.

Now, to email the error to yourself. In Global.asax.vb

Sub Application_Error(ByVal sender As Object, ByVal e As EventArgs)
’ Fires when an error occurs
Dim mBody As String
mBody = "Error: "
mBody = mBody & Server.GetLastError().InnerException.ToString()
mBody = mBody & vbCrLf & vbCrLf

    mBody = mBody & Request.Url.AbsolutePath()
    mBody = mBody & vbCrLf & vbCrLf
    mBody = mBody & Now
    mBody = mBody & vbCrLf & vbCrLf
    mBody = mBody & Server.MachineName
    mBody = mBody & vbCrLf
    mBody = mBody & Request.UserAgent
    mBody = mBody & vbCrLf


    Dim Mail As ASPEMAILLib.IMailSender ' using Persits ASPEmail - use whatever email handler you're used to and amend code as necessary
    Mail = New ASPEMAILLib.MailSender

    With Mail

        .From = "ERRORS@MySite"
        .AddAddress("[email protected]")
        .Subject = "Website App Error"
        .Body = "ERROR MSG MYSITE " & Chr(10) & Chr(10) & mBody

        Try
            .Host = "mail.mydomain.com"
            .Send()
        Catch ex_1 As Exception
            Try
                .Host = "mail.m****here.biz"
                .Send()
            Catch ex_2 As Exception
                Try
                    .Host = "mail2.m****here.biz"
                    .Send()
                Catch ex_3 As Exception
                    Try
                        .Host = "mail3.m****here.biz"
                        .Send()
                    Catch ex_4 As Exception
                        Try
                            .Host = "mail3.m****here.biz"
                            .Send()
                        Catch ex_5 As Exception
                            Try
                                .Host = "localhost"
                                .Send()
                            Catch ex_6 As Exception
                                Try
                                    .Host = "127.0.0.1"
                                    .Send()
                                Catch ex As Exception

                                End Try
                            End Try
                        End Try
                    End Try
                End Try
            End Try
        End Try

    End With

'This bit of code would add the error to a table in your database which logs the error
Try
Dim Errs As New Namespace.Helpers
Errs.AddError(mBody)
Catch ex99 As Exception
End Try

End Sub
2

Alternatively, if you e-mail the contents of Server.GetLastError().GetBaseException().GetHtmlErrorMessage() you can see the exact message and line numbers the user would normally see (of course, I’d still recommend a redirect to an error page, and only send the details to admin).

HttpCompileException ex = (HttpCompileException) ctx.Server.GetLastError().GetBaseException();
string txtError = ex.GetHtmlErrorMessage().ToString();