feat: make style but not finished

BallanceTasEditor/Styles/AccessoryIcon.cs

@@ -0,0 +1,49 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using System.Windows;
+using System.Windows.Controls;
+using System.Windows.Media;
+
+namespace BallanceTasEditor.Styles {
+
+    public class AccessoryIcon {
+        public static Object GetAccessoryIcon(DependencyObject obj) {
+            return (Object)obj.GetValue(AccessoryIconProperty);
+        }
+
+        public static void SetAccessoryIcon(DependencyObject obj, Object value) {
+            obj.SetValue(AccessoryIconProperty, value);
+        }
+
+        public static readonly DependencyProperty AccessoryIconProperty =
+            DependencyProperty.RegisterAttached("AccessoryIcon", typeof(Object), typeof(AccessoryIcon), new PropertyMetadata(null));
+    }
+
+    public class AccessoryIconContentTemplateSelector : DataTemplateSelector {
+        private static ImageSourceConverter Converter = new ImageSourceConverter();
+
+        /// <summary>
+        /// 给定的图标是已经加载的数据。
+        /// </summary>
+        public DataTemplate LoadedIconTemplate { get; set; }
+        /// <summary>
+        /// 给定的图标是来源字符串。
+        /// </summary>
+        public DataTemplate SourceIconTemplate { get; set; }
+
+        public override DataTemplate SelectTemplate(object item, DependencyObject container) {
+            var ctl = VisualTreeHelper.GetParent(container);
+            var accessoryIcon = ctl.GetValue(AccessoryIcon.AccessoryIconProperty);
+
+            if (accessoryIcon is null || !Converter.CanConvertFrom(accessoryIcon.GetType())) {
+                return LoadedIconTemplate;
+            } else {
+                return SourceIconTemplate;
+            }
+        }
+    }
+
+}