Enable Disable, all controls in a div / placeholder

 <asp:PlaceHolder ID="placeHolderMyServerControl" runat="server"></asp:PlaceHolder>

private bool condition;

protected override void CreateChildControls()
{
  base.CreateChildControls();
  MyServerControl serverControl = new MyServerControl();
  placeHolderMyServerControl.Controls.Add(serverControl);
}

protected override void OnPreRender(EventArgs e)
{
  base.OnPreRender(e);
  MyCondition();
  if(condition == true)
  {
    EnableControl(true, placeHolderMyServerControl.Controls);
  }
  else
  {
    EnableControl(false, placeHolderMyServerControl.Controls);
  }
}

/// <summary>
/// Enable Disable Control
/// </summary>
/// <param name="enabled">true or false</param>
/// <param name="controls">Controls Collection</param>
 private void EnableControl(bool enabled, ControlCollection controls)
        {
          foreach (Control childControl in control)
          {
              try
              {
                  WebControl webChildControl = (WebControl) childControl;
                  webChildControl.Enabled = enabled;
              }
              catch
              {
                 
              }
              finally
              {
                  EnableControl(enabled, childControl.Controls);
              }
          }
        }


//Your Condition
private void MyCondition()
{
//Put your own if condition
  if()
  {
  condition = true;
  }
  else
  {
  condition = false;
  }
}