实现提供了完整的弹幕功能，包括多行显示、不同颜色、头像支持、防重叠、椭圆形边框、透明度渐变、点击事件、字体样式设置、暂停/继续功能、过滤功能等。还包含了批处理队列处理逻辑、速率限制、错误处理和性能监控等功能。

YwxAppWpfDanMu/Controls/DanMuItem.xaml.cs

@@ -0,0 +1,57 @@
+using System.Windows;
+using System.Windows.Controls;
+using System.Windows.Input;
+using System.Windows.Media;
+using YwxAppWpfDanMu.Models;
+
+namespace YwxAppWpfDanMu.Controls
+{
+    public partial class DanMuItem : UserControl
+    {
+        public DanMuMessage Message { get; private set; }
+
+        public DanMuItem(DanMuMessage message)
+        {
+            InitializeComponent();
+            Message = message;
+            UpdateUI();
+        }
+
+        private void UpdateUI()
+        {
+            ContentText.Text = Message.Content;
+            ContentText.Foreground = new SolidColorBrush(Message.Color);
+            ContentText.FontSize = Message.FontSize;
+            ContentText.FontFamily = Message.FontFamily;
+            ContentText.FontWeight = Message.FontWeight;
+            ContentText.FontStyle = Message.FontStyle;
+            Opacity = Message.Opacity;
+
+            if (!string.IsNullOrEmpty(Message.AvatarUrl))
+            {
+                // 实际项目中应该使用异步加载或缓存机制
+                var image = new ImageSourceConverter().ConvertFromString(Message.AvatarUrl) as ImageSource;
+                AvatarBrush.ImageSource = image;
+            }
+            else
+            {
+                AvatarBrush.ImageSource = null;
+            }
+        }
+
+        protected override void OnMouseLeftButtonUp(MouseButtonEventArgs e)
+        {
+            base.OnMouseLeftButtonUp(e);
+            RaiseEvent(new RoutedEventArgs(ClickEvent));
+        }
+
+        public static readonly RoutedEvent ClickEvent = EventManager.RegisterRoutedEvent(
+            "Click", RoutingStrategy.Bubble, typeof(RoutedEventHandler), typeof(DanMuItem));
+
+        public event RoutedEventHandler Click
+        {
+            add { AddHandler(ClickEvent, value); }
+            remove { RemoveHandler(ClickEvent, value); }
+        }
+    }
+}