doc(Cascader): add validate sample code (#5129)

* doc: 增加本地化

* doc: 增加验证方法示例代码

Co-Authored-By: ice6 <[email protected]>
Co-Authored-By: Argo Zhang <[email protected]>

Author: ArgoZhang

src/BootstrapBlazor.Server/Components/Samples/Cascaders.razor

@@ -74,13 +74,14 @@
 </DemoBlock>
 
 <DemoBlock Title="@Localizer["Block4Title"]" Introduction="@Localizer["Block4Intro"]" Name="ValidateForm">
-    <ValidateForm Model="@Model">
+    <ValidateForm Model="@Model" @ref="ValidateForm1">
         <div class="row g-3 form-inline">
             <div class="col-12 col-sm-6">
-                <Cascader Items="@_items" @bind-Value="@Model.Address" />
+                <Cascader Items="@_items" @bind-Value="@Model.Address" IsClearable="true" />
             </div>
             <div class="col-12 col-sm-6">
                 <Button ButtonType="ButtonType.Submit">@Localizer["SubmitButtonText"]</Button>
+                <Button OnClick="OnValidate" class="ms-3">@Localizer["ValidateButtonText"]</Button>
             </div>
         </div>
     </ValidateForm>

src/BootstrapBlazor.Server/Components/Samples/Cascaders.razor.cs

@@ -30,6 +30,9 @@ public sealed partial class Cascaders
     [NotNull]
     private ConsoleLogger? NormalLogger { get; set; }
 
+    [NotNull]
+    private ValidateForm? ValidateForm1 { get; set; }
+
     private List<CascaderItem> _items = [];
 
     /// <summary>
@@ -85,6 +88,11 @@ private EventItem[] GetEvents() =>
         }
     ];
 
+    private void OnValidate()
+    {
+        ValidateForm1.Validate();
+    }
+
     /// <summary>
     /// 获得属性方法
     /// </summary>

src/BootstrapBlazor.Server/Locales/en-US.json

@@ -2306,6 +2306,7 @@
     "Att7": "The data collection",
     "Event1": "This event is triggered when the cascading selection option changes",
     "SubmitButtonText": "Submit",
+    "ValidateButtonText": "Validate",
     "item1": "Melbourne",
     "item1_child1": "Brunswick",
     "item1_child1_child": "so-and-so street",

src/BootstrapBlazor.Server/Locales/zh-CN.json

@@ -2306,6 +2306,7 @@
     "Att7": "数据集合",
     "Event1": "级联选择选项改变时触发此事件",
     "SubmitButtonText": "提交",
+    "ValidateButtonText": "验证",
     "item1": "北京",
     "item1_child1": "Brunswick",
     "item1_child1_child": "so-and-so street",