Finding Control

rstelma · September 1st, 2009, 02:41 PM

Hi,

I'm trying to show/hide controls depending on DB results. I can find the labels and set the value but I have no idea how to find the HTMLTableRow and set the Visible attribute so that I can show/hide that row.

For Each oDR In oDS.Tables(0).Rows
Dim lblVal As Label = Page.FindControl("lbl" & oDR("TankDefName"))
lblVal.Text = oDR("TankDataDesc")
Dim tdrVisible As HtmlTableRow = Page.FindControl("tr" & oDR("TankDefName"))
Next

You're help is greatly apprecaited.

Thanks,
Richard

Imar · September 5th, 2009, 06:43 AM

Hi Richard,

Can you provide a bit more information? For example, where and how did you define the table row?

Imar

rstelma · September 6th, 2009, 01:26 AM

Hi Imar,

Thanks for the reply. Very much appreciated.

This is what I have now that is working. I'm able to get and assign the values to the labels fine. Actually this is someone else's code on my team and I'm looking at this and I don't know why the variable, Dim lblval As Label, is defined within the loop. Does that make any difference?

Code:

Dim SQL As String = "SELECT TankDefID, TankDefName, TankDataDesc FROM TankDefinitions WHERE RuleID = " & _RuleID 
Dim oDA As New SqlDataAdapter(SQL, _oConn)
Dim oDS As New DataSet
Dim oDR As DataRow
oDA.Fill(oDS)

If oDS.Tables(0).Rows.Count > 0 Then
    For Each oDR In oDS.Tables(0).Rows
    Dim lblVal As Label = Page.FindControl("lbl" & oDR("TankDefName"))
    lblVal.Text = oDR("TankDataDesc")
Next

Oops.

In my previous code I had.

Code:

    Dim tdrVisible As HtmlTableRow = Page.FindControl("tr" & oDR("TankDefName"))

However, the id for the table tag is id=tdrTankBit1 and so forth and not trTankBit1. I don't know if that even is going to make any difference. The other developer has the page checked out now so I can't try that now.

I'll get the page, change the "tr" to "tdr" and get the exact line and error that it's generating.

If you have any ideas in the meant, they would be very much appreciated.

Thanks,
Richard

Imar · September 6th, 2009, 06:44 AM

Hi Richard,

Apparently, lblVal is used to dynamically find controls in the page. Normally, you would just us this:

lblVal.Text = "SomeText"

provided you have a Label like this in the code:

<asp:Label ID="lblVal" runat="server" />

However, the code is dynamically find the right labels based on the TankDefName from your database.

You can do the same trick with tables and rows (or any other HTML element), provided you give them an ID and runat attribute:

<tr id="SomeId" runat="server">

Then you can program against the SomeId row...

Hope this clarifies things a bit.

Cheers,

Imar

rstelma · September 7th, 2009, 03:20 AM

Hi Imar,

I'm such a ding dong. I was defining the table row id's as 'tdr' plus the value in the database.

Code:

<tr id="tdrSMint1" runat="server" />

All I had to do to make this work was to change "tr" to "tdr".

And that's probably why you asked to see the front page code.

Code:

Dim tdrVisible As HtmlTableRow = Page.FindControl("tr" &  oDR("TankDefName"))

To this:

Code:

Dim tdrVisible As HtmlTableRow = Page.FindControl("tdr" &  oDR("TankDefName"))

She worky. Like a dream.

Thanks so much for your reply. Extreme thanks.

Richard