Help on DataSets

[Dot Net Daddy]

Hello,

I am creating an application using asp.net 2.0. But I am stuck
somewhere. I want to get values from a DataSet one by one on every
Page_Load. So I wrote my code in Page_Load but it didnt work, giving a
warning. Here is my code:

Protected Sub Page_Load(ByVal sender As Object, ByVal e As
System.EventArgs) Handles Me.Load
Dim ds As DataSet1
Dim test As String
test = ds.Tables("pictureID").Rows(0)("pictureID").ToString
Label1.Text = test
End Sub
 

And the Warning:

Variable 'ds' is used before it has been assigned a value. A null
reference exception could result at runtime.
How can I handle this warning. Did I wrote the code in wrong place?

I created my DataSet using the menu in Visual Web Developer (Visual
Studio 2005). So I did not write any code for it.

Am I assigning the ds right?
I also assigned it as DataSet1TableAdapter. But it didnt work also. I
am a rookie so any help is appreciated.

[Cor Ligthert [MVP]]

DotNetDaddy,

If you want to get individual results focus you than on the datatable. The
dataset is just a very extended wrapper arround that (and around the
relations to that).

Your error is because "ds" in your code is only a placeholder address for an
object which is not filled yet (Is Nothing). You have to set it to, to the
actual object as is created. (Or use that direct)

Cor

"Dot Net Daddy" <ca********@gmail.comschreef in bericht
news:11*********************@m73g2000cwd.googlegro ups.com...

Hello,

I am creating an application using asp.net 2.0. But I am stuck
somewhere. I want to get values from a DataSet one by one on every
Page_Load. So I wrote my code in Page_Load but it didnt work, giving a
warning. Here is my code:

   Protected Sub Page_Load(ByVal sender As Object, ByVal e As
System.EventArgs) Handles Me.Load
       Dim ds As DataSet1
       Dim test As String
       test = ds.Tables("pictureID").Rows(0)("pictureID").ToString
       Label1.Text = test
   End Sub
 

And the Warning:

Variable 'ds' is used before it has been assigned a value. A null
reference exception could result at runtime.
How can I handle this warning. Did I wrote the code in wrong place?

I created my DataSet using the menu in Visual Web Developer (Visual
Studio 2005). So I did not write any code for it.

Am I assigning the ds right?
I also assigned it as DataSet1TableAdapter. But it didnt work also. I
am a rookie so any help is appreciated.

[tomb]

You need to make ds = New DataSet1, then populate the dataset with data.

T

Dot Net Daddy wrote:

>Hello,

I am creating an application using asp.net 2.0. But I am stuck
somewhere. I want to get values from a DataSet one by one on every
Page_Load. So I wrote my code in Page_Load but it didnt work, giving a
warning. Here is my code:

   Protected Sub Page_Load(ByVal sender As Object, ByVal e As
System.EventArgs) Handles Me.Load
       Dim ds As DataSet1
       Dim test As String
       test = ds.Tables("pictureID").Rows(0)("pictureID").ToString
       Label1.Text = test
   End Sub

And the Warning:

Variable 'ds' is used before it has been assigned a value. A null
reference exception could result at runtime.
How can I handle this warning. Did I wrote the code in wrong place?

I created my DataSet using the menu in Visual Web Developer (Visual
Studio 2005). So I did not write any code for it.

Am I assigning the ds right?
I also assigned it as DataSet1TableAdapter. But it didnt work also. I
am a rookie so any help is appreciated.