---
title: ViewPageBase.VIEWSTATE_CTRL_ENUM
summary: API reference for ViewPageBase.VIEWSTATE_CTRL_ENUM.
status: draft
owner: SAIF Doc Gen
last_reviewed: 2026-08-17
library: SAIF.Presentation.Web.MVC
reference_type: package
---

# ViewPageBase.VIEWSTATE_CTRL_ENUM

`ViewPageBase.VIEWSTATE_CTRL_ENUM` is the public nested enum consumed by `ViewPageBase.ViewStateInSession` to opt a page out of the default page-embedded ViewState and into session-backed storage instead, either for external users only or unconditionally for all users ([BR-MVC-030](../../business-rules.md#br-mvc-030-view-state-may-be-moved-into-session-for-externalall-users)). It exists because the framework's own `PageStatePersister` override needs an explicit, per-page decision on this trade-off rather than a single global switch.

## Purpose
- Selects the ViewState persistence strategy for a page instance: standard page-embedded state, session-backed state limited to non-internal callers, or session-backed state for every caller.
- Backs the `EXT_VIEWSTATE_SESSION` configuration fallback, which the overridden `PageStatePersister` property consults when this enum is left at its default.

## Context
- Namespace: `SAIF.Presentation.Web.MVC`*
- Assembly/package: `SAIF.Presentation.Web.MVC`

## Public members
| Member | Signature | Purpose |
| --- | --- | --- |
| `NONE` | `NONE` | Default. ViewState is persisted using the standard ASP.NET page-embedded mechanism |
| `EXTERNAL_USERS` | `EXTERNAL_USERS` | ViewState is moved into session storage only when the current caller's address is not on the internal network (i.e. not matching `10.*`) |
| `ALL_USERS` | `ALL_USERS` | ViewState is unconditionally moved into session storage for every caller |

## Behavioral notes
- Per the type's own developer documentation comment, this setting should only be changed with guidance and support of the architecture team, reflecting its impact on server memory and session size.*
- When `ViewStateInSession` is left at `NONE`, the `EXT_VIEWSTATE_SESSION` `AppSettings` key can still force session-backed persistence for external callers, so `NONE` does not guarantee page-embedded ViewState in every deployment.

> **Note:** Statements marked with `*` were inferred from code structure, naming conventions, or contextual evidence where direct confirmation was not available in source artifacts.

## Sources
- SAIF.Presentation.Web.MVC/ViewPageBase.aspx.vb