feat: add avalonia basic ComboBox style.

src/Avalonia/HandyControlDemo_Avalonia/ViewModel/Common/InputElementDemoViewModel.cs

@@ -1,5 +1,9 @@
+using System.Collections.Generic;
 using System.ComponentModel.DataAnnotations;
+using System.Globalization;
 using CommunityToolkit.Mvvm.ComponentModel;
+using HandyControlDemo.Properties.Langs;
+using HandyControlDemo.Tools.Converter;
 
 namespace HandyControlDemo.ViewModel;
 
@@ -20,4 +24,23 @@ public partial class InputElementDemoViewModel : ObservableValidator
     [ObservableProperty] private double? _doubleValue1;
 
     [ObservableProperty] private double? _doubleValue2;
+
+    [ObservableProperty] private IList<string>? _dataList;
+
+    public InputElementDemoViewModel()
+    {
+        DataList = GetComboBoxDemoDataList();
+    }
+
+    private static List<string> GetComboBoxDemoDataList()
+    {
+        var converter = new StringRepeatConverter();
+        var list = new List<string>();
+        for (int i = 1; i <= 9; i++)
+        {
+            list.Add($"{converter.Convert(Lang.Text, null!, i, CultureInfo.CurrentCulture)}{i}");
+        }
+
+        return list;
+    }
 }