Simple ViewState for compatibility (#93)

* Possible ViewState implementation?  (#93)

* Added a test to verify ViewState can be stored and retrieved

Author: csharpfritz

src/BlazorWebFormsComponents.Test/ViewState/SimpleRepeater.razor

@@ -0,0 +1,45 @@
+@inherits TestComponentBase
+
+<Fixture Test="FirstTest" Setup="Setup">
+	<ComponentUnderTest>
+		<Repeater @ref="MyRepeater" Items="Widget.SimpleWidgetList"
+							ItemType="Widget" OnUnload="OnRepeaterInit"
+							Context="Item">
+			<ItemTemplate><span>@Item.Name</span></ItemTemplate>
+			<SeparatorTemplate><hr /></SeparatorTemplate>
+		</Repeater>
+	</ComponentUnderTest>
+</Fixture>
+
+
+@code {
+
+	public Repeater<Widget> MyRepeater { get; set; }
+	int randomNumber;
+	const string ViewStateKey = "RandomNumber";
+
+	void Setup()
+	{
+
+		randomNumber = new Random().Next(100, 1000000);
+
+	}
+
+	void OnRepeaterInit(EventArgs args)
+	{
+
+		MyRepeater.ViewState.Add(ViewStateKey, randomNumber);
+
+	}
+
+	void FirstTest()
+	{
+
+		var cut = GetComponentUnderTest();
+
+		MyRepeater.ViewState[ViewStateKey].ShouldBe(randomNumber);
+
+	}
+
+
+}

src/BlazorWebFormsComponents/BaseWebFormsComponent.cs

@@ -20,9 +20,9 @@ public abstract class BaseWebFormsComponent : ComponentBase, IAsyncDisposable
 		public string ID { get; set; }
 
 		/// <summary>
-		/// 🚨🚨 ViewState is not available in Blazor 🚨🚨
+		/// While ViewState is supported by this library, this parameter does nothing
 		/// </summary>
-		[Parameter(), Obsolete("ViewState is not available in Blazor")]
+		[Parameter(), Obsolete("ViewState is supported, but EnableViewState does nothing")]
 		public bool EnableViewState { get; set; }
 
 		/// <summary>
@@ -63,6 +63,13 @@ public abstract class BaseWebFormsComponent : ComponentBase, IAsyncDisposable
 		[Parameter]
 		public short TabIndex { get; set; }
 
+		/// <summary>
+		/// ViewState is supported for compatibility with those components and pages that add and retrieve items from ViewState.!--  It is not binary compatible, but is syntax compatible
+		/// </summary>
+		/// <value></value>
+		[Obsolete("ViewState is supported for compatibility and is discouraged for future use")]
+		public Dictionary<string,object> ViewState { get; } = new Dictionary<string, object>();
+
 		/// <summary>
 		/// Is the content of this component rendered and visible to your users?
 		/// </summary>