FindControl() method for Dynamically Nested Controls on PostBack

How do you get a specific nested control of dynamically created controls (i开发者_运维问答.e. the child of a dynamic control)? The FindControl() method does not work because it only deals with TopLevel dynamic controls I believe.

You need to recurse through your controls: (C# code)

   public static Control FindControl(Control parentControl, string fieldName)
    {
        if (parentControl != null && parentControl.HasControls())
        {
            Control c = parentControl.FindControl(fieldName);
            if (c != null)
            {
                return c;
            }

            // if arrived here, then not found on this level, so search deeper

            // loop through collection
            foreach (Control ctrl in parentControl.Controls)
            {
                // any child controls?
                if (ctrl.HasControls())
                {
                    // try and find there
                    Control c2 = FindControl(ctrl, fieldName);
                    if (c2 != null)
                    {
                        return c2; // found it!
                    }
                }
            }
        }

        return null; // found nothing (in this branch)
    }

This is an extension method I've used in times past. I've found that using it as an extension method makes the code a little more expressive, but that's just preference.

/// <summary>
/// Extension method that will recursively search the control's children for a control with the given ID.
/// </summary>
/// <param name="parent">The control who's children should be searched</param>
/// <param name="controlID">The ID of the control to find</param>
/// <returns></returns>
public static Control FindControlRecursive(this Control parent, string controlID)
{
    if (!String.IsNullOrEmpty(parent.ClientID) && parent.ClientID.Equals(controlID)) return parent;

    System.Web.UI.Control control = null;
    foreach (System.Web.UI.Control c in parent.Controls)
    {
        control = c.FindControlRecursive(controlID);
        if (control != null)
            break;
    }
    return control;
}