feat: 增加阈值参数

Author: ArgoZhang

src/BootstrapBlazor/Components/IntersectionObserver/LoadMore.razor

@@ -1,7 +1,7 @@
 @namespace BootstrapBlazor.Components
 @inherits BootstrapModuleComponentBase
 
-<IntersectionObserver OnIntersecting="OnIntersecting" Threshold="1" AutoUnobserveWhenIntersection="false">
+<IntersectionObserver OnIntersecting="OnIntersecting" Threshold="@Threshold" AutoUnobserveWhenIntersection="false">
     <IntersectionObserverItem>
         <div class="bb-intersection-loading">
             @if (CanLoading)

src/BootstrapBlazor/Components/IntersectionObserver/LoadMore.razor.cs

@@ -12,6 +12,12 @@ namespace BootstrapBlazor.Components;
 /// </summary>
 public partial class LoadMore
 {
+    /// <summary>
+    /// 获得/设置 触底元素触发 <see cref="OnLoadMoreAsync"/> 阈值 默认为 1
+    /// </summary>
+    [Parameter]
+    public string Threshold { get; set; } = "1";
+
     /// <summary>
     /// 获得/设置 触底回调方法 <see cref="CanLoading"/> 为 true 时才触发此回调方法
     /// </summary>