asp.net gridview checkbox selection

Question

Need some help to solve this.

I have a gridview and inside the gridview I have a checkbox and after clicking the checkbox, I am doing a postback event and trying to update this particular row only on the database.

This is my gridview checkbox code. see the OnCheckedChanged.

<asp:TemplateField HeaderText="Sample">
  <ItemTemplate>
     <asp:CheckBox runat="server" 
                   ID="chkSample" 
                   Checked='<%# Bind("Sample") %>' 
                   OnCheckedChanged="UpdateSupplyLed" 
                   AutoPostBack="True">
    </asp:CheckBox> 
  </ItemTemplate>
</asp:TemplateField>

Code:

protected void UpdateSupplyLed(object sender, EventArgs e)
{
    foreach (GridViewRow di in SamplingGridView.Rows)    
    {        
        CheckBox chkBx = (CheckBox)di.FindControl("chkSample");
        if (chkBx != null && chkBx.Checked)
        {
            //update database logic here.
        }
    }
}

The above code works fine but it is getting me all the checkboxes that are checked irresepective of the one that I just checked. I don't want all of them.

How can I get the only one row value that have been just checked. Some of the rows might have been checked already because the status is true for those records and I don't want to update those records.

I think I've got my question right!

Update: The answer is:

protected void UpdateSupplyLed(object sender, EventArgs e)
{
    CheckBox chkSampleStatus = sender as CheckBox;        
    bool sample = chkSampleStatus.Checked;            
    GridViewRow row = chkSampleStatus.NamingContainer as GridViewRow;        
    TextBox txtId = row.FindControl("Id") as TextBox;            
    int id = Int32.Parse(txtId.Text);
}

Answer 1

Try this:

CheckBox chkBx = sender as CheckBox;

Rather than iterate all the rows.

I haven't used CheckBox's in a GridView in this way myself. Usually I would use the GridView's OnRowCommand event instead and use the RowIndex or CommandArgument value to update the database.

Thinking about it OnRowcommand could be tricky for a CheckBox to fire, a better solution might be sticking with the CheckChanged event of the checkbox and navigate up to the GridViewRow serverside using controls NamingContainer. Something like:

GridViewRow row = chkBx.NamingContainer as GridViewRow;

I'm assuming the goes CheckBox => Cell => Row if you Google ASP.NET NamingContainer you'll get some more specifics.