[Menu] More fixes for dispose error

src/Core/Components/Menu/FluentMenu.razor.cs

@@ -25,6 +25,7 @@
     private IMenuService? _menuService = null;
     private IJSObjectReference _jsModule = default!;
     private IJSObjectReference _anchoredRegionModule = default!;
+    private bool _disposed;
 
     private (int top, int right, int bottom, int left) _stylePositions;
 
@@ -240,14 +241,14 @@
                 }
             }
 
-            if (_jsModule is not null && _anchoredRegionModule is not null)
+            if (!_disposed)
             {
                 await _jsModule.InvokeVoidAsync("initialize", Anchor, Id, Open, _anchoredRegionModule, _dotNetHelper);
             }
         }
         else
         {
-            if (_jsModule is not null && _anchoredRegionModule is not null && _reinitializeEventListeners)
+            if (!_disposed && _reinitializeEventListeners)
             {
                 // If the menu was closed, remove its set event listeners. If it opened (ie if the menu starts out closed),
                 // we should set them now.
@@ -385,6 +386,10 @@
 
     internal async Task<bool> IsCheckedAsync(FluentMenuItem item)
     {
+        if (_jsModule is null)
+        {
+            return false;
+        }
         return await _jsModule.InvokeAsync<bool>("isChecked", item.Id);
     }
 
@@ -393,6 +398,12 @@
     /// </summary>
     public async ValueTask DisposeAsync()
     {
+        if (_disposed)
+        {
+            return;
+        }
+
+        _disposed = true;
         _dotNetHelper?.Dispose();
 
         try
@@ -401,11 +412,13 @@
             {
                 await _jsModule.InvokeVoidAsync("dispose", Anchor);
                 await _jsModule.DisposeAsync();
+                _jsModule = null;
             }
 
             if (_anchoredRegionModule is not null)
             {
                 await _anchoredRegionModule.DisposeAsync();
+                _anchoredRegionModule = null;
             }
         }
         catch (Exception ex) when (ex is JSDisconnectedException ||
@@ -414,5 +427,9 @@
             // The JSRuntime side may routinely be gone already if the reason we're disposing is that
             // the client disconnected. This is not an error.
         }
+        finally
+        {
+            GC.SuppressFinalize(this);
+        }
     }
 }