Re: Object Reference Error

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From: One Handed Man \( OHM - Terry Burns \) ("One)
Date: 07/20/04 

Date: Tue, 20 Jul 2004 20:09:57 +0100

sValue is not declared 

-- 
OHM ( Terry Burns )
 . . .  One-Handed-Man . . .
Time flies when you don't know what you're doing
"Remulac" <anonymous@discussions.microsoft.com> wrote in message
news:0c8201c46e8b$84518120$a301280a@phx.gbl...
>
> Oops!  My bad...
>
>
>     Private Sub Button1_Click(ByVal sender As
> System.Object, ByVal e As System.EventArgs) Handles
> Button1.Click
>         Try
>             Response.Write(Session("AnimalTypeID"))
>             sValue = ListBox1.Items
> (ListBox1.SelectedIndex).Value
>             Response.Write(sValue)
>         Catch ex As Exception
>             Response.Write(ex.Message)
>         End Try
>         'Server.Transfer("EditAnimalTypes.aspx")
>     End Sub
>
>
> I'm getting the following error:
>
> "Index was out of range. Must be non-negative and less
> than the size of the collection. Parameter name: index "
>
> When I take out all references to the ADO.NET objects and
> populate the listbox manually, I don't get the error any
> more.
>
> Thanks for your help.
>
>
> >-----Original Message-----
> >Thanks, but you did not include the SelectedIndexChanged
> event handler which
> >is where you code is failing
> >
> >-- 
> >
> >OHM ( Terry Burns )
> > . . .  One-Handed-Man . . .
> >
> >Time flies when you don't know what you're doing
> >
> >"Remulac" <anonymous@discussions.microsoft.com> wrote in
> message
> >news:0c0b01c46e86$88a479d0$a301280a@phx.gbl...
> >> Here's the code:
> >>
> >>
> >>
> >>     'This call is required by the Web Form Designer.
> >>     <System.Diagnostics.DebuggerStepThrough()> Private
> Sub
> >> InitializeComponent()
> >>
> >>     End Sub
> >>     Protected WithEvents ListBox1 As
> >> System.Web.UI.WebControls.ListBox
> >>     Protected WithEvents Button1 As
> >> System.Web.UI.WebControls.Button
> >>
> >>     'NOTE: The following placeholder declaration is
> >> required by the Web Form Designer.
> >>     'Do not delete or move it.
> >>     Private designerPlaceholderDeclaration As
> System.Object
> >>
> >>     Private Sub Page_Init(ByVal sender As System.Object,
> >> ByVal e As System.EventArgs) Handles MyBase.Init
> >>         'CODEGEN: This method call is required by the
> Web
> >> Form Designer
> >>         'Do not modify it using the code editor.
> >>         InitializeComponent()
> >>     End Sub
> >>
> >> #End Region
> >>
> >>     Private Sub Page_Load(ByVal sender As System.Object,
> >> ByVal e As System.EventArgs) Handles MyBase.Load
> >>         Dim cnVortex As New SqlClient.SqlConnection
> >> (System.Configuration.ConfigurationSettings.AppSettings
> >> ("ConnectionString"))
> >>         Dim cdAnimalTypes As New SqlClient.SqlCommand
> >> ("usp_GetAnimalTypes", cnVortex)
> >>         'cdAnimalTypes.CommandType =
> >> CommandType.StoredProcedure
> >>         cnVortex.Open()
> >>         Dim daAnimalTypes As New
> SqlClient.SqlDataAdapter
> >> (cdAnimalTypes)
> >>         Dim dsAnimalTypes As New DataSet
> >>         daAnimalTypes.Fill(dsAnimalTypes, "AnimalTypes")
> >>
> >>         ListBox1.DataSource = dsAnimalTypes
> >>         ListBox1.DataTextField = "ANIMAL_TYPE"
> >>         ListBox1.DataValueField = "ANIMAL_TYPE_ID"
> >>         ListBox1.DataBind()
> >>     End Sub
> >>
> >>     Private Sub Button1_Click(ByVal sender As
> >> System.Object, ByVal e As System.EventArgs) Handles
> >> Button1.Click
> >>         Try
> >>             Response.Write(Session("AnimalTypeID"))
> >>         Catch ex As Exception
> >>             Response.Write(ex.Message)
> >>         End Try
> >>         'Server.Transfer("EditAnimalTypes.aspx")
> >>     End Sub
> >>
> >>
> >>
> >>
> >>
> >> >-----Original Message-----
> >> >Post your relevant code please.
> >> >
> >> >-- 
> >> >
> >> >OHM ( Terry Burns )
> >> > . . .  One-Handed-Man . . .
> >> >
> >> >Time flies when you don't know what you're doing
> >> >
> >> >"Remulac" <anonymous@discussions.microsoft.com> wrote
> in
> >> message
> >> >news:08e401c46e6c$8c1905f0$a401280a@phx.gbl...
> >> >> Hello,
> >> >>
> >> >> I'm trying to get the value out of a dropdown list
> box
> >> and
> >> >> assign it to a variable.  When I click on the list
> box,
> >> I
> >> >> invoke this line of code.  I get the error, "Object
> >> >> reference not set to an instance of an object".
> >> >>
> >> >> The same list box is referenced successfully in the
> form
> >> >> load.  Does anyone know what might cause this
> problem?
> >> >
> >> >
> >> >.
> >> >
> >
> >
> >.
> >
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