Imported Upstream version 4.0.0~alpha1

Former-commit-id: 806294f5ded97629b74c85c09952f2a74fe182d9

external/referencesource/System.Web/UI/HiddenFieldPageStatePersister.cs

@@ -0,0 +1,57 @@
+//------------------------------------------------------------------------------
+// <copyright file="HiddenFieldPersister.cs" company="Microsoft">
+//     Copyright (c) Microsoft Corporation.  All rights reserved.
+// </copyright>
+//------------------------------------------------------------------------------
+
+namespace System.Web.UI {
+    using System;
+    using System.Collections;
+    using System.Collections.Specialized;
+    using System.IO;
+    using System.Text;
+    using System.Security.Permissions;
+    using System.Web.Security.Cryptography;
+
+    public class HiddenFieldPageStatePersister : PageStatePersister {
+        public HiddenFieldPageStatePersister(Page page) : base (page) {
+        }
+
+        public override void Load() {
+            NameValueCollection requestValueCollection = Page.RequestValueCollection;
+            if (requestValueCollection == null) {
+                return;
+            }
+
+            string viewStateString = null;
+            try {
+                viewStateString = Page.RequestViewStateString;
+
+                // VSWhidbey 160556
+                if (!String.IsNullOrEmpty(viewStateString) || !String.IsNullOrEmpty(Page.ViewStateUserKey)) {
+                    Pair combinedState = (Pair)Util.DeserializeWithAssert(StateFormatter2, viewStateString, Purpose.WebForms_HiddenFieldPageStatePersister_ClientState);
+                    ViewState = combinedState.First;
+                    ControlState = combinedState.Second;
+                }
+            }
+            catch (Exception e) {
+                // throw if this is a wrapped ViewStateException -- mac validation failed
+                if (e.InnerException is ViewStateException) {
+                    throw;
+                }
+
+                ViewStateException.ThrowViewStateError(e, viewStateString);
+            }
+        }
+
+
+        /// <devdoc>
+        ///     To be supplied.
+        /// </devdoc>
+        public override void Save() {
+            if (ViewState != null || ControlState != null) {
+                Page.ClientState = Util.SerializeWithAssert(StateFormatter2, new Pair(ViewState, ControlState), Purpose.WebForms_HiddenFieldPageStatePersister_ClientState);
+            }
+        }
+    }
+}