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ASPNet 2005

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FileInfo And DirectoryInfo Class








Web Service


WebChart Control (keywords: Graph Bar Chart)

PanelBar 3.0 & WebMenu 2.0 Samples



ServerHtmlEncode To Prevent Scripting Attacks…

My Send/Receive WebService




How to make a button the Defualt Button on-enter-key:

'Make the Lookup Button fire when "ENTER" is hit... **********

        Page.RegisterHiddenField("__EVENTTARGET", cmdLookup.ClientID)



The reason for this (besides occasional mis-designed SQL statement) is, that not all necessary permissions are set. User IUSR_<machine name> has to have permissions:

  1. for the directory the Access database resides in (right-click on the directory in Explorer, select "Properties," "Security", if the "Security" Tab is missing, go into "Tools," "Folder Options," and deactivate "Simple File sharing")
  2. for the Access database itself ("Tools", "Security", "User and Group Permissions")


How To Disable A Button After The User Clicks It So It Is Not Clicked Twice


The Solution In your Page_Load function, inject some client side code by adding an onlclick attribute to your button control. My example below does three things, it changes the text of the button, disables it, then causes a postback to fire. The reason for the last step, is that once you disable the button, you can no longer submit the form in the normal way. I've used the GetPostBackEventReference method to ensure that the __doPostBack client side function is included on the page.


Public Class WebForm1

    Inherits System.Web.UI.Page


    Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

        'Put user code to initialize the page here

        Button1.Attributes.Add("onclick", "Button1.value='Please wait...';Button1.disabled = true;" +    GetPostBackEventReference(Button1))

    End Sub


    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click


        Label1.Text = DateTime.Now.ToString()

    End Sub

End Class




Validate the session…


    Function ValidSession() As Boolean


        If Session.IsNewSession = False Then

            'Getting into this "If" statement means that we arrived at this page with a

            'session already created for us.


            If Request.UrlReferrer() Is Nothing Then

                'This scenario represents a user typing into his address bar the our url with a

                'sesion id from a previous session...

                Return False


                'This scenario represents a link from another web site with a

                'session id, (from a previous session), embedded in the link...

                Dim sReferringURL As String = Request.UrlReferrer.ToString

                Dim sCurrentUrl As String = Request.Url.ToString

                Dim iParen = InStr(sReferringURL, "(")

                'If iParen > 0 then the referring url could possible have a session id embedded in it...

                If iParen > 0 Then

                    'Check to see if the Referrer is a page from our web site...

                    If Mid(sReferringURL, 1, iParen - 1) <> Mid(sCurrentUrl, 1, iParen - 1) Then

                        Return False

                    End If

                End If 'iParen > 0

            End If 'Request.UrlReferrer() Is Nothing

        End If 'IsNewSession = False


        ValidSession = True


    End Function