ASP.NET stop application load from Application_Start

Question

Is there any way to prevent an ASP.NET application from loading within the Application_Start event?

Sub Application_Start(sender As Object, e As EventArgs)
    Try
        Dim path As String = Server.MapPath("~/")
        Dim src As String = System.IO.File.ReadAllText(path & "src.js")
        Dim check As String = System.IO.File.ReadAllText(path & "check.js")

        If Not String.Equals(src, check, StringComparison.Ordinal) Then
            'Stop application from loading here
        End If
    Catch ex As Exception
    End Try
End Sub

Missing some context here...if the app isn't supposed to do anything, then shut it down or [`app_offline.htm`](http://stackoverflow.com/a/55310/304683). — EdSF, May 24 '15 at 14:31

score 1 · Answer 1 · answered Apr 29 '17 at 14:16

If you want to do some pre-checks and prevent the application from starting if the check fails, you can throw an exception in a static constructor of the HttpApplication:

Sub New()
    Dim path As String = Server.MapPath("~/")
    Dim src As String = System.IO.File.ReadAllText(path & "src.js")
    Dim check As String = System.IO.File.ReadAllText(path & "check.js")

    If Not String.Equals(src, check, StringComparison.Ordinal) Then
        Throw New System.Exception("Cannot start-up application, because...")
    End If
End Sub

This will prevent the application from being instantiated, and every following request will fail. If the check succeeds, it will not re-check on every request.

score 0 · Answer 2 · answered May 24 '15 at 13:46

0

You can try something like this:

Sub  Application_AuthenticateRequest(sender As Object, e As EventArgs)     
    If Not String.Equals(src, check, StringComparison.Ordinal) Then
         HttpContext.Current.Response.End();
    End If

answered May 24 '15 at 13:46

Rudy

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Looks like that fires on every page request, I guess I would have to store those two strings in two HttpRuntime.Cache variables maybe in order to access them without hitting the file system every page load? – wayofthefuture May 24 '15 at 13:55
@Dude2TheN Yes, you're right, but that is not the scope of the answer. I really don't know what are you trying to achieve. Maybe some kind of custom authentication? `HttpContext.Current.Response.End();` is what you are asking for. `Application_Start` will run only once when the web app is loaded in IIS, that is why I used `Application_AuthenticateRequest`. – Rudy May 24 '15 at 14:47

ASP.NET stop application load from Application_Start

2 Answers2