Greetings All

I'm learning to use arraylist and structures but I'm getting a
System.NullReferenceException Error and I'm not sure why. I followed the
VB.net book all I did was change the names. See code below

Structure SppElementProperties
Dim Element As String
Dim North As String
Dim South As String
Dim Wave As String
Dim Wake As String
End Structure

Private Sub testform2_Load(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles MyBase.Load
Dim SppElementProperties As ArrayList
Dim Spp As New SppElementProperties

Spp.Element = "Element1"
Spp.North = "North1"
Spp.South = "South1"
Spp.Wave = "Wave1"
Spp.Wake = "Wake1"
SppElementProperties.Add(Spp) 'This is the Line I get an error on
Spp.Element = "Element2"
Spp.North = "North2"
Spp.South = "South2"
Spp.Wave = "Wave2"
Spp.Wake = "Wake2"
SppElementProperties.Add(Spp)
Spp.Element = "Element3"
Spp.North = "North3"
Spp.South = "South3"
Spp.Wave = "Wave3"
Spp.Wake = "Wake3"
SppElementProperties.Add(Spp)
Dim REnum As IEnumerator
REnum = SppElementProperties.GetEnumerator
While REnum.MoveNext
MessageBox.Show(REnum.Current)
End While

End Sub

TIA

Sal
> Dim SppElementProperties As ArrayList
> Dim Spp As New SppElementProperties
>
> Spp.Element = "Element1"
> Spp.North = "North1"
> Spp.South = "South1"
> Spp.Wave = "Wave1"
> Spp.Wake = "Wake1"
> SppElementProperties.Add(Spp) 'This is the Line I get an error on

You never initialize the SppElementProperties variable.

Try:
> Dim SppElementProperties As New ArrayList

Hope this helps
Jay


"sal" <(E-Mail Removed)> wrote in message
news:Xns95AAB11E089salsppnet@216.77.188.18...
> Greetings All
>
> I'm learning to use arraylist and structures but I'm getting a
> System.NullReferenceException Error and I'm not sure why. I followed the
> VB.net book all I did was change the names. See code below
>
> Structure SppElementProperties
> Dim Element As String
> Dim North As String
> Dim South As String
> Dim Wave As String
> Dim Wake As String
> End Structure
>
> Private Sub testform2_Load(ByVal sender As System.Object, ByVal e As
> System.EventArgs) Handles MyBase.Load
> Dim SppElementProperties As ArrayList
> Dim Spp As New SppElementProperties
>
> Spp.Element = "Element1"
> Spp.North = "North1"
> Spp.South = "South1"
> Spp.Wave = "Wave1"
> Spp.Wake = "Wake1"
> SppElementProperties.Add(Spp) 'This is the Line I get an error on
> Spp.Element = "Element2"
> Spp.North = "North2"
> Spp.South = "South2"
> Spp.Wave = "Wave2"
> Spp.Wake = "Wake2"
> SppElementProperties.Add(Spp)
> Spp.Element = "Element3"
> Spp.North = "North3"
> Spp.South = "South3"
> Spp.Wave = "Wave3"
> Spp.Wake = "Wake3"
> SppElementProperties.Add(Spp)
> Dim REnum As IEnumerator
> REnum = SppElementProperties.GetEnumerator
> While REnum.MoveNext
> MessageBox.Show(REnum.Current)
> End While
>
> End Sub
>
> TIA

Thanks that fixed it..I'm glad it was something simple
:-)

"Jay B. Harlow [MVP - Outlook]" <(E-Mail Removed)> wrote in
news:(E-Mail Removed):

> Sal
>> Dim SppElementProperties As ArrayList
>> Dim Spp As New SppElementProperties
>>
>> Spp.Element = "Element1"
>> Spp.North = "North1"
>> Spp.South = "South1"
>> Spp.Wave = "Wave1"
>> Spp.Wake = "Wake1"
>> SppElementProperties.Add(Spp) 'This is the Line I get an error
>> on
>
> You never initialize the SppElementProperties variable.
>
> Try:
>> Dim SppElementProperties As New ArrayList
>
> Hope this helps
> Jay
>
>
> "sal" <(E-Mail Removed)> wrote in message
> news:Xns95AAB11E089salsppnet@216.77.188.18...
>> Greetings All
>>
>> I'm learning to use arraylist and structures but I'm getting a
>> System.NullReferenceException Error and I'm not sure why. I followed
>> the VB.net book all I did was change the names. See code below
>>
>> Structure SppElementProperties
>> Dim Element As String
>> Dim North As String
>> Dim South As String
>> Dim Wave As String
>> Dim Wake As String
>> End Structure
>>
>> Private Sub testform2_Load(ByVal sender As System.Object, ByVal e As
>> System.EventArgs) Handles MyBase.Load
>> Dim SppElementProperties As ArrayList
>> Dim Spp As New SppElementProperties
>>
>> Spp.Element = "Element1"
>> Spp.North = "North1"
>> Spp.South = "South1"
>> Spp.Wave = "Wave1"
>> Spp.Wake = "Wake1"
>> SppElementProperties.Add(Spp) 'This is the Line I get an error
>> on Spp.Element = "Element2"
>> Spp.North = "North2"
>> Spp.South = "South2"
>> Spp.Wave = "Wave2"
>> Spp.Wake = "Wake2"
>> SppElementProperties.Add(Spp)
>> Spp.Element = "Element3"
>> Spp.North = "North3"
>> Spp.South = "South3"
>> Spp.Wave = "Wave3"
>> Spp.Wake = "Wake3"
>> SppElementProperties.Add(Spp)
>> Dim REnum As IEnumerator
>> REnum = SppElementProperties.GetEnumerator
>> While REnum.MoveNext
>> MessageBox.Show(REnum.Current)
>> End While
>>
>> End Sub
>>
>> TIA
>
>
>