How to implement and Validate CSRF method in asp.net

Question

I am using asp.net application and I dont know how to implement and validate CSRF tokens in asp.net.I want to validate these tokens in each request.

Can anyone help me?

And I have added this following code in Masterpage

private const string AntiXsrfTokenKey = "__AntiXsrfToken";
private const string AntiXsrfUserNameKey = "__AntiXsrfUserName";
private string _antiXsrfTokenValue;
protected void Page_Init(object sender, EventArgs e) {
 var requestCookie = Request.Cookies[AntiXsrfTokenKey];
 Guid requestCookieGuidValue;
 if (requestCookie != null && Guid.TryParse(requestCookie.Value, out requestCookieGuidValue)) {
  _antiXsrfTokenValue = requestCookie.Value;
  Page.ViewStateUserKey = _antiXsrfTokenValue;

 } else {
  _antiXsrfTokenValue = Guid.NewGuid().ToString("N");
  Page.ViewStateUserKey = _antiXsrfTokenValue;
  var responseCookie = new HttpCookie(AntiXsrfTokenKey) {
   HttpOnly = true,
    Value = _antiXsrfTokenValue
  };
  if (FormsAuthentication.RequireSSL && Request.IsSecureConnection) {
   responseCookie.Secure = true;
  }
  Response.Cookies.Set(responseCookie);
 }

 Page.PreLoad += master_Page_PreLoad;
}

protected void master_Page_PreLoad(object sender, EventArgs e) {
 try {
  if (!IsPostBack) {
   ViewState[AntiXsrfTokenKey] = Page.ViewStateUserKey;
   ViewState[AntiXsrfUserNameKey] = Context.User.Identity.Name ? ? String.Empty;
  } else {
   //Validate the Anti-XSRF token
   if ((string) ViewState[AntiXsrfTokenKey] != _antiXsrfTokenValue || (string) ViewState[AntiXsrfUserNameKey] != (Context.User.Identity.Name ? ? String.Empty)) {
    throw new InvalidOperationException("Validation of " + "Anti-XSRF token failed.");
   }
  }
 } catch (Exception ex) {
  activityLog.Write("MasterPage->PageLoad->Exception->" + ex.Message.ToString());
  Session.Clear();
  Session.RemoveAll();
  Session.Abandon();
  Response.Cookies["ASP.NET_SessionId"].Expires = DateTime.Now.AddYears(-30);
  Response.Cookies.Add(new HttpCookie("ASP.NET_SessionId", ""));
  ScriptManager.RegisterStartupScript(this, GetType(), "DeleteCookie", "DeleteCookie();", true);
  Response.Redirect("Default.aspx", false);
 }
}