fix(Select): can not switch Value when data type is SelectedItem on Virtual mode (#4850)

* fix: 修复虚拟数据无法切换数据问题

* test: 更新单元测试

* refactor: 精简代码

* Revert "refactor: 精简代码"

This reverts commit 114d3ad.

* refactor: 重构代码

* test: 更新单元测试

Author: ArgoZhang

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

@@ -264,7 +264,7 @@ private SelectedItem? SelectedRow
         var item = Rows.Find(i => i.Value == CurrentValueAsString)
             ?? Rows.Find(i => i.Active)
             ?? Rows.Where(i => !i.IsDisabled).FirstOrDefault()
-            ?? GetVirtualizeItem();
+            ?? GetVirtualizeItem(CurrentValueAsString);
 
         if (item != null)
         {
@@ -376,22 +376,23 @@ protected override bool TryParseValueFromString(string value, [MaybeNullWhen(fal
 
     private bool TryParseSelectItem(string value, [MaybeNullWhen(false)] out TValue result, out string? validationErrorMessage)
     {
-        SelectedItem = Items.FirstOrDefault(i => i.Value == value)
-            ?? GetVirtualizeItem();
+        SelectedItem = Rows.FirstOrDefault(i => i.Value == value)
+            ?? GetVirtualizeItem(value);
 
         // support SelectedItem? type
         result = SelectedItem != null ? (TValue)(object)SelectedItem : default;
         validationErrorMessage = "";
         return SelectedItem != null;
     }
 
-    private SelectedItem? GetVirtualizeItem()
+    private SelectedItem? GetVirtualizeItem(string value)
     {
-        return OnQueryAsync == null ? null : GetSelectedItem();
-
-        SelectedItem? GetSelectedItem() => ValueType == typeof(SelectedItem)
-            ? (SelectedItem)(object)Value
-            : new SelectedItem(CurrentValueAsString, DefaultVirtualizeItemText ?? CurrentValueAsString);
+        SelectedItem? item = null;
+        if (_result.Items != null)
+        {
+            item = _result.Items.FirstOrDefault(i => i.Value == value) ?? new SelectedItem(value, DefaultVirtualizeItemText ?? value);
+        }
+        return item;
     }
 
     /// <summary>

test/UnitTest/Components/SelectTest.cs

@@ -747,7 +747,7 @@ public async Task IsVirtualize_OnQueryAsync_Clearable_Ok()
     }
 
     [Fact]
-    public void IsVirtualize_BindValue()
+    public async Task IsVirtualize_BindValue()
     {
         var value = new SelectedItem("3", "Test 3");
         var cut = Context.RenderComponent<Select<SelectedItem>>(pb =>
@@ -772,24 +772,21 @@ public void IsVirtualize_BindValue()
             });
         });
 
-        cut.InvokeAsync(() =>
-        {
-            var input = cut.Find(".form-select");
-            Assert.Equal("Test 3", input.GetAttribute("value"));
-        });
-        cut.Contains("Test 3");
+        var input = cut.Find(".form-select");
+        Assert.Null(input.GetAttribute("value"));
+
         var select = cut.Instance;
         Assert.Equal("3", select.Value?.Value);
 
-        cut.InvokeAsync(() =>
+        var item = cut.Find(".dropdown-item");
+        await cut.InvokeAsync(() =>
         {
-            var item = cut.Find(".dropdown-item");
             item.Click();
-            Assert.Equal("1", value.Value);
-
-            var input = cut.Find(".form-select");
-            Assert.Equal("Test1", input.GetAttribute("value"));
         });
+        Assert.Equal("1", value.Value);
+
+        input = cut.Find(".form-select");
+        Assert.Equal("Test1", input.GetAttribute("value"));
     }
 
     [Fact]