gridview findcontrol returning empty ""

Question

i am trying to read from a textbox within a gridview by using this code

    protected void Button1_Click(object sender, EventArgs e)
    {
        foreach (GridViewRow row in GridView1.Rows)
        {
            string textBoxText = ((TextBox)row.FindControl("numTC")).Text;
            Response.Write(textBoxText);

        }
    }

this code keeps returning "" (empty)

any idea why this is hapenning?

Thanks

i am adding the values manually trough the website, its reading them all as "" and not null — Karl, Aug 17 '11 at 07:41
When you click the button are the values in the Textboxes on the page changing back to blank? — Tim B James, Aug 17 '11 at 08:24
@Karl: are you doing databinding of grid in code or is it done automatically? could you show us your gridview asp? — Răzvan Flavius Panda, Aug 17 '11 at 08:37

Tim B James · Accepted Answer · 2011-08-17T08:34:17.263

4

Make sure that you are not re-binding the GridView on the PostBack of the page. This may be the issue.

EDITS

Make sure that the code for Binding the GridView is within the code below:

C#

if ( !Page.IsPostBack ){
    // Code to bind the control
}

VB

If Not Page.IsPostBack Then
    ' Code to bind the control
End If

Otherwise what happens is that the controls is "rebuilt" and the values are all lost within the TextBox's

edited Aug 17 '11 at 08:34

answered Aug 17 '11 at 08:25

Tim B James

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the gridview is binding on page_load, and when i click the button it seems to be re loading the page, how can i arrange that? – Karl Aug 17 '11 at 08:30
Where have you added this code? Don't add it to the button click – Tim B James Aug 17 '11 at 08:38
then i understood you wrong, where should i add it? should i do it where it is doing the databind of the gridview? – Karl Aug 17 '11 at 08:44
Yes, were you are binding the data to the GridView. – Tim B James Aug 17 '11 at 08:45

Răzvan Flavius Panda · Answer 2 · 2011-08-17T08:46:11.290

1

UPDATE:

For testing purposes, try doing GridView1.DataBind(); at the begining of your method.

Try debugging like this:

Set a breakpoint at the end of the Button1_Click method.

Run the site in debug mode (F5).

When executions stops at end of Button1_Click, open the Immediate Window located at bottom of screen.

Type there:

GridView1.Rows and see if it contains the number of rows it should.

Should be something like:

System.Web.UI.WebControls.GridViewRowCollection} Count: 53 <-- number of rows

If it does return more than 0 rows then type:

GridView1.Rows[0].Controls and see if it returns the right number of controls on a row.

I could access controls on a row directly using GridView1.Rows[2].Controls[n] where n is the order of the control in the row.

Also try (TextBox)GridView1.Rows[0].FindControl("numTC") and see what it returns.

edited Aug 17 '11 at 08:46

answered Aug 17 '11 at 08:05

Răzvan Flavius Panda

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ive done as you said, the number of rows shows as 79, and the (TextBox)GridView1.Rows[0].FindControl("numTC") still returns "" – Karl Aug 17 '11 at 08:15
@Karl: the only thing i can think of is that the control you are searching has a different ID from "numTC", i made that mistake once and didn't notice :) – Răzvan Flavius Panda Aug 17 '11 at 08:19
ive tried that too..but unfortunatley it wasnt the case, ill keep trying to see whats wrong, thanks anyway – Karl Aug 17 '11 at 08:23
@Karl: does GridView1.Rows[0].FindControl("numTC") return null? – Răzvan Flavius Panda Aug 17 '11 at 08:34
when i do response.write, it just returns System.Web.UI.WebControls.TextBox – Karl Aug 17 '11 at 08:41
@Karl: i mean to use the command GridView1.Rows[0].FindControl("numTC") in Immediate Window, if it returns null it means it couldn't find the control. Does it return null? – Răzvan Flavius Panda Aug 17 '11 at 08:43
problem solved, it was because the data was rebinding every time i pressed the button, thanks for your help – Karl Aug 17 '11 at 08:49

gridview findcontrol returning empty ""

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