优化更新代码，添加界面功能并整合

WPFluent/Converters/ToastIconVisibilityConverter.cs

@@ -0,0 +1,32 @@
+using System;
+using System.Globalization;
+using System.Windows;
+using System.Windows.Data;
+
+using WPFluent.Controls;
+
+namespace WPFluent.Converters;
+
+[ValueConversion(typeof(ToastIcon), typeof(Visibility))]
+internal sealed class ToastIconVisibilityConverter : IValueConverter
+{
+    public static ToastIconVisibilityConverter New => new();
+
+    public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
+    {
+        if (value is ToastIcon icon)
+        {
+            return icon switch
+            {
+                ToastIcon.None => Visibility.Collapsed,
+                _ => Visibility.Visible,
+            };
+        }
+        return Visibility.Collapsed;
+    }
+
+    public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
+    {
+        return DependencyProperty.UnsetValue;
+    }
+}