refactor: 兼容 null 项

Author: ArgoZhang

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

@@ -1128,11 +1128,11 @@ private async Task ReloadColumnVisibleFromBrowserAsync()
         if (!string.IsNullOrEmpty(ClientTableName))
         {
             // 读取浏览器配置
-            var clientColumns = await InvokeAsync<List<ColumnVisibleItem>>("reloadColumnList", ClientTableName);
+            var clientColumns = await InvokeAsync<List<ColumnVisibleItem?>>("reloadColumnList", ClientTableName);
             clientColumns ??= [];
             foreach (var column in _visibleColumns)
             {
-                var item = clientColumns.FirstOrDefault(i => i.Name == column.Name);
+                var item = clientColumns.FirstOrDefault(i => i?.Name == column.Name);
                 if (item != null)
                 {
                     column.Visible = item.Visible;

src/BootstrapBlazor/Converter/ColumnVisibleItemConverter.cs

@@ -48,7 +48,7 @@ public class ColumnVisibleItemConverter : JsonConverter<ColumnVisibleItem>
                 }
             }
         }
-        return new ColumnVisibleItem(name ?? "", visible);
+        return string.IsNullOrEmpty(name) ? null : new ColumnVisibleItem(name, visible);
     }
 
     /// <summary>