feat: 增加 OverscanCount 参数

Author: ArgoZhang

src/BootstrapBlazor/Components/Table/Table.razor

@@ -369,13 +369,13 @@
             {
                 @if (Items != null)
                 {
-                    <Virtualize ItemSize="RowHeight" OverscanCount="10" Items="@Items.ToList()" ChildContent="RenderRow">
+                    <Virtualize ItemSize="RowHeight" OverscanCount="@OverscanCount" Items="@Items.ToList()" ChildContent="RenderRow">
                     </Virtualize>
                 }
                 else
                 {
                     <Virtualize @ref="_virtualizeElement"
-                                ItemSize="RowHeight" OverscanCount="10" Placeholder="RenderPlaceholderRow"
+                                ItemSize="RowHeight" OverscanCount="@OverscanCount" Placeholder="RenderPlaceholderRow"
                                 ItemsProvider="LoadItems" ItemContent="RenderRow">
                     </Virtualize>
                 }

src/BootstrapBlazor/Components/Table/Table.razor.cs

@@ -370,6 +370,13 @@ private string GetSortTooltip(ITableColumn col) => SortName != col.GetFieldName(
     [Parameter]
     public float RowHeight { get; set; } = 38f;
 
+    /// <summary>
+    /// Gets or sets the overscan count for virtual scrolling. Default is 10.
+    /// </summary>
+    /// <remarks>Effective when <see cref="ScrollMode"/> is set to <see cref="ScrollMode.Virtual"/>.</remarks>
+    [Parameter]
+    public int OverscanCount { get; set; } = 10;
+
     [Inject]
     [NotNull]
     private IOptionsMonitor<BootstrapBlazorOptions>? Options { get; set; }