Find Control

[shapper]

Hello,

I created nested pages as follows:

Base.master
| ------ Global.master
| ------ TwoColumns.master
| ------ Default.aspx

In Global.master.vb I added a textbox in runtime:

1 Protected WithEvents tbUsername As New TextBox
2 cphGlobal.Controls.Add(tbUsername)

In Global.master.vb I also added a a button at runtime where I want to
access tbUsername when the button is clicked:

1 Private Sub ibSubmit_Click(ByVal sender As Object, ByVal e As
ImageClickEventArgs) Handles ibSubmit.Click
2
3 Dim ibSubmit As ImageButton = CType(sender, ImageButton)
4
5 Dim tbUsername As TextBox =
CType(Page.FindControl("tbUsername"), TextBox)
6 If String.IsNullOrEmpty(tbUsername.Text) Then
7 tbUsername.CssClass = "tbSystemError"
8 End If
9
10 End Sub

When I click the button I get the error, on line 6:

"Object reference not set to an instance of an object."

I tried many variations of my code. For example:

1 Dim tbUsername As TextBox = CType(Page.FindControl("tbUsername"),
TextBox)

However, I am not able to make this work.

Could someone, please, help me out?

I don't know what else to do.

Thanks,

Miguel

 

[Brennan Stehling]

shapper,

Place a few breakpoints throughout your code and then walk it line by
line with the debugger. That will help you identify exactly where it
is hitting the null reference.

More Info on Debugging:
http://brennan.offwhite.net/blog/2006/09/12/debugging-aspnet-20-with-visual-studio-2005/

Brennan Stehling
http://brennan.offwhite.net/blog/

 

[bruce barker]

findcontrol does not do a recursive search. it only checks the current
control collection. do a find of cphGlobal.Controls. also its does not
appear that you are naming the control (set ID), so a default is assigned.

-- bruce (sqlwork.com)