第一：
private void Button1_Click(object sender, System.EventArgs e)
{
Response.Redirect(Request.Url.ToString());
}
第二：
private void Button2_Click(object sender, System.EventArgs e)
{
Response.Write("<script language=javascript>window.location.href=document.URL;</script>");
}
第三：
private void Button3_Click(object sender, System.EventArgs e)
{
Response.AddHeader("Refresh","0");
}