refactor: 重构 OnClearValue 方法

Author: ArgoZhang

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

@@ -208,7 +208,7 @@ private List<SelectedItem> Rows
         }
     }
 
-    private string? PreviousValue { get; set; }
+    private string? _lastSelectedValueString;
 
     private string? PlaceholderString => SelectedItems.Count == 0 ? PlaceHolder : null;
 
@@ -243,9 +243,9 @@ protected override void OnParametersSet()
 
         // 通过 Value 对集合进行赋值
         var _currentValue = CurrentValueAsString;
-        if (PreviousValue != _currentValue)
+        if (_lastSelectedValueString != _currentValue)
         {
-            PreviousValue = _currentValue;
+            _lastSelectedValueString = _currentValue;
             var list = _currentValue.Split(',', StringSplitOptions.RemoveEmptyEntries);
 
             SelectedItems.Clear();
@@ -322,24 +322,20 @@ private IEnumerable<SelectedItem> FilterBySearchText(IEnumerable<SelectedItem> s
         ? source
         : source.Where(i => i.Text.Contains(SearchText, StringComparison));
 
-    private async Task OnClearValue()
+    /// <summary>
+    /// <inheritdoc/>
+    /// </summary>
+    /// <returns></returns>
+    protected override async Task OnClearValue()
     {
-        if (ShowSearch)
-        {
-            ClearSearchText();
-        }
-        if (OnClearAsync != null)
-        {
-            await OnClearAsync();
-        }
+        await base.OnClearValue();
 
         if (OnQueryAsync != null)
         {
             await _virtualizeElement.RefreshDataAsync();
         }
 
-        PreviousValue = string.Empty;
-        CurrentValue = default;
+        _lastSelectedValueString = string.Empty;
         SelectedItems.Clear();
     }
 
@@ -499,8 +495,7 @@ private async Task SetValue()
             await OnSelectedItemsChanged.Invoke(SelectedItems);
         }
 
-        PreviousValue = CurrentValueAsString;
-
+        _lastSelectedValueString = CurrentValueAsString;
         if (!ValueChanged.HasDelegate)
         {
             StateHasChanged();

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

@@ -470,24 +470,19 @@ private async Task SelectedItemChanged(SelectedItem item)
     /// </summary>
     public void Add(SelectedItem item) => _children.Add(item);
 
-    private async Task OnClearValue()
+    /// <summary>
+    /// <inheritdoc/>
+    /// </summary>
+    /// <returns></returns>
+    protected override async Task OnClearValue()
     {
-        if (ShowSearch)
-        {
-            ClearSearchText();
-        }
-        if (OnClearAsync != null)
-        {
-            await OnClearAsync();
-        }
+        await base.OnClearValue();
 
         if (OnQueryAsync != null)
         {
             await _virtualizeElement.RefreshDataAsync();
         }
-
         _lastSelectedValueString = string.Empty;
-        CurrentValue = default;
         SelectedItem = null;
     }
 

src/BootstrapBlazor/Components/Select/SelectBase.cs

@@ -217,4 +217,21 @@ protected override void OnParametersSet()
     /// Clears the search text.
     /// </summary>
     public void ClearSearchText() => SearchText = null;
+
+    /// <summary>
+    /// Clears the selected value.
+    /// </summary>
+    /// <returns></returns>
+    protected virtual async Task OnClearValue()
+    {
+        if (ShowSearch)
+        {
+            ClearSearchText();
+        }
+        if (OnClearAsync != null)
+        {
+            await OnClearAsync();
+        }
+        CurrentValue = default;
+    }
 }

src/BootstrapBlazor/Components/SelectGeneric/SelectGeneric.razor.cs

@@ -449,30 +449,17 @@ private async Task ValueTypeChanged(SelectedItem<TValue> item)
     /// <param name="item"></param>
     public void Add(SelectedItem<TValue> item) => _children.Add(item);
 
-    private async Task OnClearValue()
+    /// <summary>
+    /// <inheritdoc/>
+    /// </summary>
+    /// <returns></returns>
+    protected override async Task OnClearValue()
     {
-        if (ShowSearch)
-        {
-            ClearSearchText();
-        }
-        if (OnClearAsync != null)
-        {
-            await OnClearAsync();
-        }
+        await base.OnClearValue();
 
-        SelectedItem<TValue>? item;
         if (OnQueryAsync != null)
         {
             await VirtualizeElement.RefreshDataAsync();
-            item = _result.Items.FirstOrDefault();
-        }
-        else
-        {
-            item = Items.FirstOrDefault();
-        }
-        if (item != null)
-        {
-            await SelectedItemChanged(item);
         }
     }