SharePoint基于表单身份验证的自定义登录页

protected void btnLogin_Click(object sender, EventArgs e)
{
    var username = this.loginFormsUser.FindControl("UserName") as TextBox;
    var password = this.loginFormsUser.FindControl("password") as TextBox;

    if (string.IsNullOrEmpty(username.Text))
    {
        var error = this.loginFormsUser.FindControl("FailureText") as Label;
        error.Text = "请输入用户名";
        return;
    }
    else
    {
        if (string.IsNullOrEmpty(password.Text))
        {
            var error = this.loginFormsUser.FindControl("FailureText") as Label;
            error.Text = "请输入密码";
            return;
        }
    }

    try
    {
        SetFBACookie(HttpContext.Current.Request, username.Text, password.Text);
        var returnUrl = Request["ReturnUrl"];
        Response.Redirect(returnUrl);
    }
    catch (Exception ex)
    {
        var label = this.loginFormsUser.FindControl("FailureText") as Label;
        label.Text = ex.ToString();
    }
}

private static void SetFBACookie(HttpRequest r, string username, string cookieValue)
{
    using (SPSite s = new SPSite(r.Url.AbsoluteUri))
    {
        SPIisSettings iis = s.WebApplication.IisSettings[SPUrlZone.Default];
        SPFormsAuthenticationProvider fap = iis.FormsClaimsAuthenticationProvider;
        SecurityToken token = SPSecurityContext.SecurityTokenForFormsAuthentication(new Uri(r.Url.GetComponents(UriComponents.Scheme | UriComponents.HostAndPort, UriFormat.Unescaped), UriKind.Absolute), fap.MembershipProvider, fap.RoleProvider, username, cookieValue, SPFormsAuthenticationOption.PersistentSignInRequest);
        SPFederationAuthenticationModule fam = SPFederationAuthenticationModule.Current;
        fam.SetPrincipalAndWriteSessionToken(token);
    }
}