如果您使用的是 ASP.NET WebForms 模板附带的默认成员资格,您应该执行以下操作来检索用户:
if (this.User != null && this.User.Identity.IsAuthenticated)
{
  var userName = HttpContext.Current.User.Identity.Name;
}
您所说的新模型是ClaimsPrincipal. 独特的区别是这个基于声明的安全,它与旧版本完全兼容,但更强大。
编辑:
要将用户添加到某些Role程序中,您应该这样做,传递用户名和角色名:
if (this.User != null && this.User.Identity.IsAuthenticated)
{
  var userName = HttpContext.Current.User.Identity.Name;
  System.Web.Security.Roles.AddUserToRole(userName, "Role Name");    
}
使用新的基于声明的安全性
if (this.User != null && this.User.Identity.IsAuthenticated)
{
  var userName = HttpContext.Current.User.Identity.Name;
  ClaimsPrincipal cp = (ClaimsPrincipal)HttpContext.Current.User;
  GenericIdentity genericIdentity;
  ClaimsIdentity claimsIdentity;
  Claim claim;
  genericIdentity = new GenericIdentity(userName, "Custom Claims Principal");
  claimsIdentity = new ClaimsIdentity(genericIdentity);
  claim = new Claim(ClaimTypes.Role, "Role Name");
  claimsIdentity.AddClaim(claim);
  cp.AddIdentity(claimsIdentity);
}