private dynamic DoLogin()
{
var user = _userDb.Login(Request.Form.username, Request.Form.password);
if (user == null)
{
ViewBag.Error = "用户名或密码错误！";
return(View["user/login"]);
}
else
{
User = user;
return(new RedirectResponse(Request.Form.returnurl == null ? "/user" : Request.Form.returnurl));
}
}