feat(Select): redesign IsClearable function

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

@@ -87,19 +87,6 @@
     </div>
 </DemoBlock>
 
-<DemoBlock Title="@Localizer["SelectsClearableTitle"]"
-           Introduction="@Localizer["SelectsClearableIntro"]"
-           Name="IsClearable">
-    <div class="row g-3">
-        <div class="col-12 col-sm-6">
-            <Select Color="Color.Primary" IsClearable="true" Items="ClearableItems" Value="ClearableModel.Name"></Select>
-        </div>
-        <div class="col-12 col-sm-6">
-            <Select Color="Color.Primary" IsClearable="true" Items="Items" Value="ClearableModel.Name"></Select>
-        </div>
-    </div>
-</DemoBlock>
-
 <DemoBlock Title="@Localizer["SelectsBindingSelectedItemTitle"]"
            Introduction="@Localizer["SelectsBindingSelectedItemIntro"]"
            Name="BindingSelectedItem">
@@ -348,6 +335,28 @@
     </div>
 </DemoBlock>
 
+<DemoBlock Title="@Localizer["SelectsClearableTitle"]"
+           Introduction="@Localizer["SelectsClearableIntro"]"
+           Name="IsClearable">
+    <section ignore>
+        <p>@((MarkupString)Localizer["SelectsClearableDesc"].Value)</p>
+    </section>
+    <div class="row g-3">
+        <div class="col-12 col-sm-6">
+            <Select IsClearable="true" Items="ClearableItems" Value="ClearableModel.NullableName" ShowLabel="true" DisplayText="string?"></Select>
+        </div>
+        <div class="col-12 col-sm-6">
+            <Select IsClearable="true" Items="Items" Value="ClearableModel.Name" ShowLabel="true" DisplayText="string"></Select>
+        </div>
+        <div class="col-12 col-sm-6">
+            <Select IsClearable="true" Items="IntItems" Value="ClearableModel.NullableCount" ShowLabel="true" DisplayText="int?"></Select>
+        </div>
+        <div class="col-12 col-sm-6">
+            <Select IsClearable="true" Items="IntItems" Value="ClearableModel.Count" ShowLabel="true" DisplayText="int"></Select>
+        </div>
+    </div>
+</DemoBlock>
+
 <DemoBlock Title="@Localizer["SelectsConfirmSelectTitle"]"
            Introduction="@Localizer["SelectsConfirmSelectIntro"]"
            Name="ConfirmSelect">
@@ -412,22 +421,23 @@
 <DemoBlock Title="@Localizer["SelectsVirtualizeTitle"]"
            Introduction="@Localizer["SelectsVirtualizeIntro"]"
            Name="IsVirtualize">
-    <section ignore>@((MarkupString)Localizer["SelectsVirtualizeDescription"].Value)</section>
-
-    <div class="row mb-3">
-        <div class="col-12 col-sm-6">
-            <BootstrapInputGroup>
-                <BootstrapInputGroupLabel DisplayText="ShowSearch" />
-                <Checkbox @bind-Value="@_showSearch" />
-            </BootstrapInputGroup>
-        </div>
-        <div class="col-12 col-sm-6">
-            <BootstrapInputGroup>
-                <BootstrapInputGroupLabel DisplayText="IsClearable" />
-                <Checkbox @bind-Value="@_isClearable" />
-            </BootstrapInputGroup>
+    <section ignore>
+        <p>@((MarkupString)Localizer["SelectsVirtualizeDescription"].Value)</p>
+        <div class="row mb-3">
+            <div class="col-12 col-sm-6">
+                <BootstrapInputGroup>
+                    <BootstrapInputGroupLabel DisplayText="ShowSearch" />
+                    <Checkbox @bind-Value="@_showSearch" />
+                </BootstrapInputGroup>
+            </div>
+            <div class="col-12 col-sm-6">
+                <BootstrapInputGroup>
+                    <BootstrapInputGroupLabel DisplayText="IsClearable" />
+                    <Checkbox @bind-Value="@_isClearable" />
+                </BootstrapInputGroup>
+            </div>
         </div>
-    </div>
+    </section>
 
     <p class="code-label">1. 使用 OnQueryAsync 作为数据源</p>
     <div class="row mb-3">

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

@@ -51,7 +51,7 @@ public sealed partial class Selects
 
     private string? _fooName;
 
-    private List<SelectedItem> _enumValueDemoItems = [
+    private readonly List<SelectedItem> _enumValueDemoItems = [
         new("0", "Primary"),
         new("1", "Middle")
     ];
@@ -101,7 +101,18 @@ private Task OnItemChanged(SelectedItem item)
 
     private Foo BindingModel { get; set; } = new Foo();
 
-    private Foo ClearableModel { get; set; } = new Foo();
+    private MockModel ClearableModel { get; set; } = new();
+
+    class MockModel
+    {
+        public string? NullableName { get; set; }
+
+        public string Name { get; set; } = "";
+
+        public int Count { get; set; } = 1;
+
+        public int? NullableCount { get; set; }
+    }
 
     private SelectedItem? Item { get; set; }
 
@@ -230,6 +241,14 @@ private string GetSelectedBoolItemString()
         new("abcde", "abcde")
     ];
 
+    private readonly SelectedItem[] IntItems =
+    [
+        new("1", "1"),
+        new("12", "12"),
+        new("123", "123"),
+        new("1234", "1234")
+    ];
+
     private static Task<bool> OnBeforeSelectedItemChange(SelectedItem item)
     {
         return Task.FromResult(true);

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

@@ -3111,6 +3111,7 @@
     "SelectsBindingIntro": "The values in the text box change as you change the drop-down option by binding the <code>Model.Name</code> property to the component with <code>Select</code>",
     "SelectsClearableTitle": "Clearable",
     "SelectsClearableIntro": "You can clear Select using a clear icon",
+    "SelectsClearableDesc": "Cannot be a null integer. Setting <code>IsClearable</code> has no effect. Its default value is <b>0</b>",
     "SelectsBindingSelectedItemTitle": "Select two-way binding SelectItem type",
     "SelectsBindingSelectedItemIntro": "The values in the text box change as you change the drop-down option by binding the <code>SelectItem</code> property to the component with <code>Select</code> .",
     "SelectsCascadingTitle": "Select cascading binding",

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

@@ -3111,6 +3111,7 @@
     "SelectsBindingIntro": "通过 <code>Select</code> 组件绑定 <code>Model.Name</code> 属性，改变下拉框选项时，文本框内的数值随之改变。",
     "SelectsClearableTitle": "可清空单选",
     "SelectsClearableIntro": "包含清空按钮，可将选择器清空为初始状态",
+    "SelectsClearableDesc": "不可为空整形设置 <code>IsClearable</code> 无效，其默认值为 <b>0</b>",
     "SelectsBindingSelectedItemTitle": "Select 双向绑定 SelectItem",
     "SelectsBindingSelectedItemIntro": "通过 <code>Select</code> 组件绑定 <code>SelectItem</code> 属性，改变下拉框选项时，文本框内的数值随之改变。",
     "SelectsCascadingTitle": "Select 级联绑定",

src/BootstrapBlazor/Components/Select/Select.razor.cs

@@ -42,7 +42,7 @@ public partial class Select<TValue> : ISelect, ILookup
         .AddClass($"text-danger", IsValid.HasValue && !IsValid.Value)
         .Build();
 
-    private bool GetClearable() => IsClearable && !IsDisabled;
+    private bool GetClearable() => IsClearable && !IsDisabled && IsNullable();
 
     /// <summary>
     /// 设置当前项是否 Active 方法
@@ -294,6 +294,11 @@ private SelectedItem? SelectedRow
 
     private SelectedItem? GetSelectedRow()
     {
+        if (Value is null)
+        {
+            return null;
+        }
+
         var item = GetItemWithEnumValue()
             ?? Rows.Find(i => i.Value == CurrentValueAsString)
             ?? Rows.Find(i => i.Active)
@@ -393,7 +398,7 @@ protected override async Task OnAfterRenderAsync(bool firstRender)
     /// </summary>
     private int TotalCount { get; set; }
 
-    private List<SelectedItem> GetVirtualItems() => FilterBySearchText(GetRowsByItems()).ToList();
+    private List<SelectedItem> GetVirtualItems() => [.. FilterBySearchText(GetRowsByItems())];
 
     /// <summary>
     /// 虚拟滚动数据加载回调方法
@@ -539,7 +544,6 @@ private async Task SelectedItemChanged(SelectedItem item)
     {
         if (_lastSelectedValueString != item.Value)
         {
-
             item.Active = true;
             SelectedItem = item;
 
@@ -556,7 +560,7 @@ private async Task SelectedItemChanged(SelectedItem item)
     }
 
     /// <summary>
-    /// 添加静态下拉项方法
+    /// <inheritdoc/>
     /// </summary>
     /// <param name="item"></param>
     public void Add(SelectedItem item) => _children.Add(item);
@@ -577,22 +581,18 @@ private async Task OnClearValue()
             await OnClearAsync();
         }
 
-        SelectedItem? item;
         if (OnQueryAsync != null)
         {
             await VirtualizeElement.RefreshDataAsync();
-            item = _result.Items.FirstOrDefault();
-        }
-        else
-        {
-            item = Items.FirstOrDefault();
-        }
-        if (item != null)
-        {
-            await SelectedItemChanged(item);
         }
+
+        _lastSelectedValueString = string.Empty;
+        CurrentValue = default;
+        SelectedItem = null;
     }
 
+    private bool IsNullable() => !ValueType.IsValueType || NullableUnderlyingType != null;
+
     private string? ReadonlyString => IsEditable ? null : "readonly";
 
     private async Task OnChange(ChangeEventArgs args)

test/UnitTest/Components/SelectTest.cs

@@ -8,6 +8,7 @@
 using Microsoft.AspNetCore.Components.Web.Virtualization;
 using System.ComponentModel.DataAnnotations;
 using System.Reflection;
+using System.Runtime.CompilerServices;
 
 namespace UnitTest.Components;
 
@@ -134,7 +135,7 @@ public void Select_Lookup()
     }
 
     [Fact]
-    public void IsClearable_Ok()
+    public async Task IsClearable_Ok()
     {
         var val = "Test2";
         var cut = Context.RenderComponent<Select<string>>(pb =>
@@ -154,8 +155,8 @@ public void IsClearable_Ok()
             });
         });
         var clearButton = cut.Find(".clear-icon");
-        cut.InvokeAsync(() => clearButton.Click());
-        Assert.Empty(val);
+        await cut.InvokeAsync(() => clearButton.Click());
+        Assert.Null(val);
 
         // 提高代码覆盖率
         var select = cut;
@@ -174,6 +175,97 @@ public void IsClearable_Ok()
         validPi.SetValue(select.Instance, false);
         val = pi.GetValue(select.Instance, null)!.ToString();
         Assert.Contains("text-danger", val);
+
+        // 更改数据类型为不可为空 int
+        // IsClearable 参数无效
+        var cut1 = Context.RenderComponent<Select<int>>(pb =>
+        {
+            pb.Add(a => a.IsClearable, true);
+            pb.Add(a => a.Items, new List<SelectedItem>()
+            {
+                new("1", "Test1"),
+                new("2", "Test2"),
+                new("3", "Test3")
+            });
+            pb.Add(a => a.Value, 1);
+        });
+        cut1.DoesNotContain("clear-icon");
+    }
+
+    [Fact]
+    public void IsNullable_Ok()
+    {
+        var cut = Context.RenderComponent<Select<string>>(pb =>
+        {
+            pb.Add(a => a.Items, new List<SelectedItem>()
+            {
+                new("", "请选择"),
+                new("2", "Test2"),
+                new("3", "Test3")
+            });
+        });
+        Assert.True(IsNullable(cut.Instance));
+
+        var cut1 = Context.RenderComponent<Select<string?>>(pb =>
+        {
+            pb.Add(a => a.Items, new List<SelectedItem>()
+            {
+                new("", "请选择"),
+                new("2", "Test2"),
+                new("3", "Test3")
+            });
+        });
+        Assert.True(IsNullable(cut1.Instance));
+
+        var cut2 = Context.RenderComponent<Select<Foo>>(pb =>
+        {
+            pb.Add(a => a.Items, new List<SelectedItem>()
+            {
+                new("", "请选择"),
+                new("2", "Test2"),
+                new("3", "Test3")
+            });
+        });
+        Assert.True(IsNullable(cut2.Instance));
+
+        var cut3 = Context.RenderComponent<Select<Foo?>>(pb =>
+        {
+            pb.Add(a => a.Items, new List<SelectedItem>()
+            {
+                new("", "请选择"),
+                new("2", "Test2"),
+                new("3", "Test3")
+            });
+        });
+        Assert.True(IsNullable(cut3.Instance));
+
+        var cut4 = Context.RenderComponent<Select<int>>(pb =>
+        {
+            pb.Add(a => a.Items, new List<SelectedItem>()
+            {
+                new("", "请选择"),
+                new("2", "Test2"),
+                new("3", "Test3")
+            });
+        });
+        Assert.False(IsNullable(cut4.Instance));
+
+        var cut5 = Context.RenderComponent<Select<int?>>(pb =>
+        {
+            pb.Add(a => a.Items, new List<SelectedItem>()
+            {
+                new("", "请选择"),
+                new("2", "Test2"),
+                new("3", "Test3")
+            });
+        });
+        Assert.True(IsNullable(cut5.Instance));
+    }
+
+    private static bool IsNullable(object select)
+    {
+        var mi = select.GetType().GetMethod("IsNullable", BindingFlags.Instance | BindingFlags.NonPublic)!;
+        return (bool)mi.Invoke(select, null)!;
     }
 
     [Fact]
@@ -434,8 +526,7 @@ public void NullBool_Ok()
         });
 
         // 值为 null
-        // 候选项中无，导致默认选择第一个 Value 被更改为 true
-        Assert.True(cut.Instance.Value);
+        Assert.Null(cut.Instance.Value);
     }
 
     [Fact]
@@ -735,8 +826,8 @@ public async Task IsVirtualize_Items_Clearable_Ok()
         var button = cut.Find(".clear-icon");
         await cut.InvokeAsync(() => button.Click());
 
-        // UI 恢复 Test1
-        Assert.Equal("Test1", el.Value);
+        // 可为空数据类型 UI 为 ""
+        Assert.Equal("", el.Value);
 
         // 下拉框显示所有选项
         items = cut.FindAll(".dropdown-item");
@@ -794,8 +885,8 @@ public async Task IsVirtualize_OnQueryAsync_Clearable_Ok()
         var button = cut.Find(".clear-icon");
         await cut.InvokeAsync(() => button.Click());
 
-        // UI 恢复 Test1
-        Assert.Equal("All", el.Value);
+        // 可为空数据类型 UI 为 ""
+        Assert.Equal("", el.Value);
 
         // 下拉框显示所有选项
         Assert.True(query);