feat: 增加 OnBeforeShowContextMenu 回调方法

Author: ArgoZhang

src/BootstrapBlazor/Components/Layout/Layout.razor

@@ -133,6 +133,7 @@
           BeforeContextMenuTemplate="@BeforeTabContextMenuTemplate" ContextMenuTemplate="@TabContextMenuTemplate"
           ContextMenuRefreshIcon="@TabContextMenuRefreshIcon" ContextMenuCloseIcon="@TabContextMenuCloseIcon"
           ContextMenuCloseOtherIcon="@TabContextMenuCloseOtherIcon" ContextMenuCloseAllIcon="@TabContextMenuCloseAllIcon"
+          OnBeforeShowContextMenu="@OnBeforeShowContextMenu"
           ShowRefreshToolbarButton="ShowRefreshToolbarButton" ShowFullscreenToolbarButton="ShowFullscreenToolbarButton"
           RefreshToolbarButtonIcon="@RefreshToolbarButtonIcon" FullscreenToolbarButtonIcon="@FullscreenToolbarButtonIcon"
           RefreshToolbarTooltipText="@RefreshToolbarTooltipText" FullscreenToolbarTooltipText="@FullscreenToolbarTooltipText"

src/BootstrapBlazor/Components/Layout/Layout.razor.cs

@@ -339,6 +339,12 @@ public partial class Layout : IHandlerException
     [Parameter]
     public string? TabContextMenuCloseAllIcon { get; set; }
 
+    /// <summary>
+    /// Gets or sets before popup context menu callback. Default is null.
+    /// </summary>
+    [Parameter]
+    public Func<TabItem, Task<bool>>? OnBeforeShowContextMenu { get; set; }
+
     [Inject]
     [NotNull]
     private NavigationManager? Navigation { get; set; }