ASP.NET, VB: how to access controls inside a FormView from the code behind?

Question

I have a checkbox and a panel inside of a FormView control, and I need to access them from the code behind in order to use the checkbox to determine whether or not the panel

Answer 1

FormView has its own event framework. A normal control within a FormView won't generate the postback events you are looking for. I initially made the same mistake. I wanted, like you, to generate some kind of postback that could be intercepted at the server end. Once we get back to the server we can look at the values in checkboxes etc depending on whatever business rules apply. This is what I did.

First of all put all relevant controls within an

<EditItemTemplate> 

section within the FormView. (There are other Template tags that may be more appropriate). To generate the postback have a button (for example) like the one below. (This has to be within the EditItemTemplate section as well):

<asp:linkbutton id="UpdateButton"
    text="Update"
    commandname="Update"
    runat="server"/>

You can intercept this at the server with the FormView event ItemCommand. For example:

Private Sub FormView1_ItemCommand(sender As Object, e As System.Web.UI.WebControls.FormViewCommandEventArgs) Handles FormView1.ItemCommand
    'your code here
End Sub

Once you are back at the server you can then start looking at the various controls to see what they hold, using findControl if necessary. The button command shown above is an example so you might want to use another control.

Answer 2

In VB you need use Directcast

Dim chk As Checkbox = DirectCast(Me.FormView1.FindControl("checkgen"), Checkbox)

Answer 3

With FormView, you have to use find control, as in:

CheckBox checkGenEd = (CheckBox)formview1.FindControl("checkGenEd");
Panel panelOutcome = (Panel)formview1.FindControl("panelOutcome");

You cannot reference a control directly by ID.

HTH.