feat(BootstrapLabelSetting): add BootstrapLabelSetting component (#5274)

* feat: 增加 AddStyle 方法

* test: 增加单元测试

* refactor: use AddStyle method

* doc: 重构代码

* refactor: 重构代码

* Revert "refactor: 重构代码"

This reverts commit 37653dc.

* feat: 增加 BootstrapLabelSetting 组件

* feat: 增加 LabelWidth 参数

* feat: 实现 LabelWidth 逻辑

* test: 增加单元测试

src/BootstrapBlazor/Components/Label/BootstrapLabel.razor.cs

@@ -29,6 +29,9 @@ public partial class BootstrapLabel
     [Parameter]
     public int? LabelWidth { get; set; }
 
+    [CascadingParameter]
+    private BootstrapLabelSetting? Setting { get; set; }
+
     private bool _showTooltip;
 
     private string? ClassString => CssBuilder.Default("form-label")
@@ -52,5 +55,8 @@ protected override void OnParametersSet()
             _showTooltip = ShowLabelTooltip.Value;
         }
         Value ??= "";
+
+        // 获得级联参数的 LabelWidth
+        LabelWidth ??= Setting?.LabelWidth;
     }
 }

src/BootstrapBlazor/Components/Label/BootstrapLabelSetting.razor

@@ -0,0 +1,5 @@
+@namespace BootstrapBlazor.Components
+
+<CascadingValue Value="this" IsFixed="true">
+    @ChildContent
+</CascadingValue>

src/BootstrapBlazor/Components/Label/BootstrapLabelSetting.razor.cs

@@ -0,0 +1,24 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the Apache 2.0 License
+// See the LICENSE file in the project root for more information.
+// Maintainer: Argo Zhang([email protected]) Website: https://www.blazor.zone
+
+namespace BootstrapBlazor.Components;
+
+/// <summary>
+/// BootstrapLabelSetting 组件类
+/// </summary>
+public partial class BootstrapLabelSetting
+{
+    /// <summary>
+    /// 获得/设置 子组件
+    /// </summary>
+    [Parameter]
+    public RenderFragment? ChildContent { get; set; }
+
+    /// <summary>
+    /// 获得/设置 标签宽度 默认 null 未设置使用全局设置 <code>--bb-row-label-width</code> 值
+    /// </summary>
+    [Parameter]
+    public int? LabelWidth { get; set; }
+}

test/UnitTest/Components/BootstrapLabelTest.cs

@@ -0,0 +1,40 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the Apache 2.0 License
+// See the LICENSE file in the project root for more information.
+// Maintainer: Argo Zhang([email protected]) Website: https://www.blazor.zone
+
+namespace UnitTest.Components;
+
+public class BootstrapLabelTest : BootstrapBlazorTestBase
+{
+    [Fact]
+    public void BootstrapLabelSetting_LabelWidth_Ok()
+    {
+        var cut = Context.RenderComponent<BootstrapLabelSetting>(pb =>
+        {
+            pb.Add(a => a.LabelWidth, 120);
+            pb.AddChildContent<BootstrapLabel>();
+        });
+        Assert.Equal("<label class=\"form-label\" style=\"--bb-row-label-width: 120px;\"></label>", cut.Markup);
+
+        var label = cut.FindComponent<BootstrapLabel>();
+        label.SetParametersAndRender(pb =>
+        {
+            pb.Add(a => a.LabelWidth, 80);
+        });
+        Assert.Equal("<label class=\"form-label\" style=\"--bb-row-label-width: 80px;\"></label>", cut.Markup);
+    }
+
+    [Fact]
+    public void LabelWidth_Ok()
+    {
+        var cut = Context.RenderComponent<BootstrapLabel>();
+        Assert.Equal("<label class=\"form-label\"></label>", cut.Markup);
+
+        cut.SetParametersAndRender(pb =>
+        {
+            pb.Add(a => a.LabelWidth, 120);
+        });
+        Assert.Equal("<label class=\"form-label\" style=\"--bb-row-label-width: 120px;\"></label>", cut.Markup);
+    }
+}