[MessageBar] Implement ClearAfterNavigation on provider level

examples/Demo/Shared/Pages/MessageBar/MessageBarPage.razor

@@ -35,6 +35,23 @@
     )
 </CodeSnippet>
 
+<h2 id="sections">Sections</h2>
+<p>
+    You can use multiple message bar providers in a single page/app. In the example below you can add a message bar on the top of the window, but also
+    in the notification center or in a dialog. An area to display messages in is called a <code>Section</code>.
+
+    You can specify in wich <code>Section</code> you want your message to appear in through the <code>MessageOptions</code>.
+
+</p>
+
+<h2 id="clear">Clear message bars on navigation</h2>
+<p>
+    By default, message bars will not be removed when navigating to another page. This can be changed by setting the <code>ClearAfterNavigation</code>
+    parameter to true on a <code>FluentMenuProvider</code>. When using multiple providers (see Sections above), the parameter needs to be set for each
+    provider individually.
+    You can also set the behavior on a per message basis by using the same parameter of the <code>MessageOptions</code> class.
+</p>
+
 <h2 id="example">Examples</h2>
 
 <DemoSection Title="Message Service" Component="typeof(MessageBarDefault)">
@@ -44,7 +61,7 @@
         If you click on "Add in a dialog" multiple times, you will see that only one message is displayed.
         Once you dismiss that one, the next one will be displayed.
     </p>
-    <p>This is the advised way to use MessageBars </p>
+    <p>Using the <code>MessageService</code> is the advised way to use message bars.</p>
 </DemoSection>
 
 <DemoSection Title="Timed Messages" Component="typeof(MessageBarTimed)">
@@ -100,3 +117,5 @@
 <ApiDocumentation Component="typeof(MessageService)" />
 
 <ApiDocumentation Component="typeof(Message)" />
+
+<ApiDocumentation Component="typeof(MessageOptions)" />

examples/Demo/Shared/Shared/DemoMainLayout.razor

@@ -56,7 +56,7 @@
                 <div class="content">
                     <article id="article">
 
-                        <FluentMessageBarProvider Section="@App.MESSAGES_TOP" />
+                        <FluentMessageBarProvider Section="@App.MESSAGES_TOP" ClearAfterNavigation="true" />
 
 
                                 <CascadingValue Value=@OnRefreshTableOfContents>

src/Core/Components/MessageBar/FluentMessageBarProvider.razor.cs

@@ -1,11 +1,15 @@
 using Microsoft.AspNetCore.Components;
+using Microsoft.AspNetCore.Components.Routing;
 using Microsoft.FluentUI.AspNetCore.Components.Utilities;
 
 namespace Microsoft.FluentUI.AspNetCore.Components;
 
 /// <summary />
 public partial class FluentMessageBarProvider : FluentComponentBase, IDisposable
 {
+    [Inject]
+    private NavigationManager NavigationManager { get; set; } = default!;
+
     /// <summary />
     protected string? ClassValue => new CssBuilder(Class).Build();
 
@@ -83,7 +87,12 @@ protected override void OnInitialized()
     {
         MessageService.OnMessageItemsUpdated += OnMessageItemsUpdatedHandler;
         MessageService.OnMessageItemsUpdatedAsync += OnMessageItemsUpdatedHandlerAsync;
-        base.OnInitialized();
+
+        if (ClearAfterNavigation)
+        {
+            NavigationManager.LocationChanged += ClearMessages;
+        }
+
     }
 
     /// <summary />
@@ -92,18 +101,32 @@ protected virtual void OnMessageItemsUpdatedHandler()
         InvokeAsync(StateHasChanged);
     }
 
-    protected async virtual Task OnMessageItemsUpdatedHandlerAsync()
+    protected virtual async Task OnMessageItemsUpdatedHandlerAsync()
     {
         await Task.Run(() =>
         {
             InvokeAsync(StateHasChanged);
         });
     }
 
+    private void ClearMessages(object? sender, LocationChangedEventArgs args)
+    {
+        if (AllMessagesForCategory.Any())
+        {
+            InvokeAsync(() =>
+            {
+                MessageService.Clear(Section);
+                StateHasChanged();
+            });
+        }
+    }
+
     /// <summary />
     public void Dispose()
     {
         MessageService.OnMessageItemsUpdated -= OnMessageItemsUpdatedHandler;
         MessageService.OnMessageItemsUpdatedAsync -= OnMessageItemsUpdatedHandlerAsync;
+
+        NavigationManager.LocationChanged -= ClearMessages;
     }
 }

src/Core/Components/MessageBar/Services/MessageService.cs

@@ -62,7 +62,7 @@ public virtual IEnumerable<Message> MessagesToShow(int count = 5, string? sectio
         MessageLock.EnterReadLock();
         try
         {
-            IEnumerable<Message>? messages = string.IsNullOrEmpty(section)
+            var messages = string.IsNullOrEmpty(section)
                        ? MessageList
                        : MessageList.Where(x => x.Section == section);
 
@@ -301,11 +301,11 @@ private void RemoveMessageItems(string? section = null)
             return;
         }
 
-        IEnumerable<Message>? messages = string.IsNullOrEmpty(section)
+        var messages = string.IsNullOrEmpty(section)
             ? MessageList
             : MessageList.Where(i => i.Section == section);
 
-        foreach (Message message in messages)
+        foreach (var message in messages)
         {
             message.OnClose -= Remove;
         }