How to access content page controls from master page in asp.net

Question

it is very easy to access master page control from content page like

protected void Page_Load(object sender, EventArgs e)
{
    // content page load event
          


        

Answer 1

In master page button click event should access page contents by:-

protected void Button1_Click(object sender, EventArgs e)
{
    TextBox TextBox1 = (TextBox)ContentPlaceHolder1.FindControl("TextBox1");
    if (TextBox1 != null)
    {
        Label1.Text = TextBox1.Text;
    }
}