refactor(FilterProvider): refactoring to improve code readability (#6031)

Author: ArgoZhang

src/BootstrapBlazor/Components/Filters/FilterProvider.razor

@@ -3,14 +3,14 @@
 
 @if (IsHeaderRow)
 {
-    @RenderFilter()
+    @RenderFilter
 }
 else
 {
     <div class="card filter-item">
         <div class="card-header"><span>@Title</span></div>
         <div class="card-body">
-            @RenderFilter()
+            @RenderFilter
         </div>
         <div class="card-footer">
             <div class="d-flex flex-fill">
@@ -25,3 +25,10 @@ else
         </div>
     </div>
 }
+
+@code {
+    RenderFragment RenderFilter =>
+    @<CascadingValue IsFixed="false" Value="@FilterContext">
+        @ChildContent
+    </CascadingValue>;
+}

src/BootstrapBlazor/Components/Filters/FilterProvider.razor.cs

@@ -153,20 +153,10 @@ private void OnClickMinus()
         }
     }
 
-    /// <summary>
-    /// 渲染自定义过滤器方法
-    /// </summary>
-    /// <returns></returns>
-    protected virtual RenderFragment RenderFilter() => builder =>
+    private FilterContext FilterContext => new()
     {
-        builder.OpenComponent<CascadingValue<FilterContext>>(0);
-        builder.AddAttribute(1, nameof(CascadingValue<FilterContext>.Value), new FilterContext()
-        {
-            Count = Count,
-            FieldKey = FieldKey,
-            IsHeaderRow = IsHeaderRow
-        });
-        builder.AddAttribute(2, nameof(CascadingValue<FilterContext>.ChildContent), ChildContent);
-        builder.CloseComponent();
+        Count = Count,
+        FieldKey = FieldKey,
+        IsHeaderRow = IsHeaderRow
     };
 }