Question

1 – Is it possible to handle controls that generate dynamically via java script or other way in page ?

2- What is the mechanism of find control, if I have my TextBox in UpdatePanel ?

For Example how can i get value of controls(textBox) that has been added to table :

for (int i = 0; i < rowsCount; i++)
        {
            TableRow row = new TableRow();
            for (int j = 0; j < colsCount; j++)
            {
                TableCell cell = new TableCell();
                TextBox tb = new TextBox();
                tb.ID = "txtSabeghe_" + (i + 1) + "Col_" + (j + 1);
                cell.Controls.Add(tb);
                row.Cells.Add(cell);
            }
            Table5.Rows.Add(row);
        }

Table And button of Function Both Are in Update Panel to Avoid Postback

Answer 1

Your question is too general, but I’ll do my best to answer based on what I “think” you’re asking.

1. Yes, all .net controls render as HTML in the DOM so you can handle them exactly as you would a DOM element, except that .net renders DOM with extra stuff in the id attribute i.e. ctl_001_ etc, so you need to use the ClientID property. You can of course set the ClientIDMode to Static in the web.config as this article shows, this will leave the IDs as you specify.

   <asp:TextBox runat="server" id="mytextbox" />
   

   And your script.

   // without ClientIDMode = 'Static'
   var element = document.getElementById('<%=mytextbox.ClientID%>');
   
   // with ClientIDMode = 'Static'
   var element = document.getElementById('mytextbox');
   

2. Control.FindControl is a server side method (of the Control base class) that takes the ID (as a string) of the control you want to find, which can be used as follows.

   <asp:Panel runat="server" id="mypanel">
       <asp:TextBox runat="server" id="mytextbox" />
   </asp:Panel>
   

   And in your code behind.

   TextBox tbx = mypanel.FindControl("mytextbox");
   

EDIT – Finding a control using master pages

If you want to find your control using master pages, you’re best filtering through the parents like so.

// parent place holder in master page
ContentPlaceHolder cph = (ContentPlaceHolder)this.Master.FindControl("ContentPlaceHolderID");

// parent panel in content place holder
UpdatePanel pnl = cph.FindControl("UpdatePanelID");

// child of parent that you're interested in
TextBox tbx = pnl.FindControl("TextBoxID");