How to refer control declare outside loop

Question

0.00/5 (No votes)

See more:

Hello friends,
Glad to back with get suggestion from u. Let me tell you, I tried out following code

Private Sub createDCList(ByVal objDT As DataTable)
        Dim row As DataRow
        Dim intIndex As Integer = 0
        Dim pnlCheckList As New Panel
        pnlCheckList.Direction = ContentDirection.LeftToRight   'POSITIONING OF CONTROLS IN PANEL
        pnlCheckList = Page.FindControl("pnlJCList")
        For Each row In objDT.Rows
            Dim lblHeading As New Label
            lblHeading.Text = row.Item("CheckListName").ToString() & ":"
            lblHeading.ID = "lblHeading_" & intIndex
            pnlCheckList.Controls.Add(lblHeading)          'Line Error
            intIndex = intIndex + 1
        Next
    End Sub

I was getting error on line Error saying:
Object reference nto set to an instance of an object

As per my knowledge inside FOR LOOP, pnlCheckList is not available
Any idea how to refer it?

Thanks in advance

Posted 8-Apr-11 0:31am

dhage.prashant01

Add a Solution

4 solutions

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Venkatesh Mookkan · Answer 1 · 2011-04-08T00:35:00

Solution 1

If pnlJCList exists in the Page you use that object directly. Why are using FindControl in the first place.

This should work:

VB

Private Sub createDCList(ByVal objDT As DataTable)
        Dim row As DataRow
        Dim intIndex As Integer = 0
        For Each row In objDT.Rows
            Dim lblHeading As New Label
            lblHeading.Text = row.Item("CheckListName").ToString() & ":"
            lblHeading.ID = "lblHeading_" & intIndex
            pnlJCList.Controls.Add(lblHeading)          'Line Error
            intIndex = intIndex + 1
        Next
End Sub

Mark it as answer if it is helpful

Posted 8-Apr-11 0:35am

Venkatesh Mookkan

Updated 8-Apr-11 5:05am

v3

Comments

Eduard Keilholz 8-Apr-11 6:37am

sharp, +5

Venkatesh Mookkan 8-Apr-11 6:47am

Thanks.

dhage.prashant01 8-Apr-11 6:43am

so i should find panel in for loop?

Venkatesh Mookkan 8-Apr-11 6:48am

Use pnlJCList object directly. No need to use FindControl.

dhage.prashant01 8-Apr-11 7:13am

great help. . .

Venkatesh Mookkan 8-Apr-11 11:05am

Mark it as answer if it helps you.

OriginalGriff · Answer 2 · 2011-04-08T00:37:00

Solution 3

If you look at the MSDN[^] documentation for Page.FindControl, then you will find:

Return Value
Type: System.Web.UI.Control
The specified control, or null if the specified control does not exist.

Check your names!

Posted 8-Apr-11 0:37am

OriginalGriff

Eduard Keilholz · Answer 3 · 2011-04-08T00:37:00

Solution 2

The answer is simple, if the panel doen't exist at the time you run the code, you cannot access it. You're going to have to move the moment of running this code to a cetrain moment where the panel does exist.

Posted 8-Apr-11 0:37am

Eduard Keilholz

web works · Answer 4 · 2011-04-08T07:46:00

Solution 4

why are you doing "Dim pnlCheckList As New Panel" and not putting panel control on page and then do whatever you want?

Posted 8-Apr-11 7:46am

web works

Comments

web works 8-Apr-11 13:50pm

and if it is yr requirement then pnlCheckList has to be available on page to access!!