添加 Toast 通知功能，优化鼠标悬浮和键盘导航逻辑，增强用户交互体验。临时禁用鼠标悬浮功能以避免误操作，并在列表边界触发时提供反馈。

src/components/VirtualList.vue

@@ -25,10 +25,14 @@ const props = defineProps({
   frozen: {
     type: Boolean,
     default: false
+  },
+  disableHover: {
+    type: Boolean,
+    default: false
   }
 })
 
-const emit = defineEmits(['select', 'click', 'contextmenu'])
+const emit = defineEmits(['select', 'click', 'contextmenu', 'showToast'])
 
 // 计算列表项实际总高度
 const totalItemHeight = computed(() => 
@@ -133,9 +137,13 @@ const handleScroll = debounce(() => {
   }
 }, props.config.scrollDebounceTime)
 
-// 鼠标移入处理
+// 添加一个状态来控制是否禁用鼠标悬浮
+const disableHover = ref(false)
+let hoverTimer = null
+
+// 修改鼠标移入处理函数
 function handleMouseEnter(index) {
-  if (props.frozen) return  // 如果列表被冻结，不响应鼠标移入
+  if (props.frozen || disableHover.value || props.disableHover) return // 增加 props.disableHover 的判断
   if (!isKeyboardNavigating.value) {
     selectedIndex.value = index
     emit('select', { ...props.data[index], index })
@@ -143,11 +151,17 @@ function handleMouseEnter(index) {
   }
 }
 
-// 键盘事件处理
+// 添加记录上次到达边界的时间
+const lastReachBoundaryTime = ref({
+  top: 0,
+  bottom: 0
+})
+
+// 修改键盘事件处理函数
 function handleKeyDown(e) {
-  if (props.frozen) return  // 如果列表被冻结，不响应键盘事件
+  if (props.frozen) return
+
   if (e.key === 'Enter') {
-    // 回车键触发点击事件
     if (selectedIndex.value >= 0 && selectedIndex.value < props.data.length) {
       const item = props.data[selectedIndex.value]
       emit('click', { ...item, index: selectedIndex.value })
@@ -157,26 +171,59 @@ function handleKeyDown(e) {
     
     const isFirstItem = selectedIndex.value === 0
     const isLastItem = selectedIndex.value === props.data.length - 1
+    const now = Date.now()
     
-    // 如果已经在第一项还按上键，或在最后一项还按下键，则不处理
-    if ((e.key === 'ArrowUp' && isFirstItem) || 
-        (e.key === 'ArrowDown' && isLastItem)) {
+    if (e.key === 'ArrowUp' && isFirstItem) {
+      const timeSinceLastTop = now - lastReachBoundaryTime.value.top
+      if (timeSinceLastTop < 5000) {
+        // 5秒内再次点击，跳转到底部
+        disableHover.value = true // 禁用鼠标悬浮
+        selectedIndex.value = props.data.length - 1
+        emit('select', { ...props.data[selectedIndex.value], index: selectedIndex.value })
+        ensureSelectedItemVisible()
+        // 1秒后恢复鼠标悬浮功能
+        if (hoverTimer) clearTimeout(hoverTimer)
+        hoverTimer = setTimeout(() => {
+          disableHover.value = false
+        }, 1000)
+      } else {
+        lastReachBoundaryTime.value.top = now
+        emit('showToast', '已经到列表顶端，再次点击将回到列表底端')
+      }
       return
     }
     
+    if (e.key === 'ArrowDown' && isLastItem) {
+      const timeSinceLastBottom = now - lastReachBoundaryTime.value.bottom
+      if (timeSinceLastBottom < 5000) {
+        // 5秒内再次点击，跳转到顶部
+        disableHover.value = true // 禁用鼠标悬浮
+        selectedIndex.value = 0
+        emit('select', { ...props.data[selectedIndex.value], index: selectedIndex.value })
+        ensureSelectedItemVisible()
+        // 1秒后恢复鼠标悬浮功能
+        if (hoverTimer) clearTimeout(hoverTimer)
+        hoverTimer = setTimeout(() => {
+          disableHover.value = false
+        }, 1000)
+      } else {
+        lastReachBoundaryTime.value.bottom = now
+        emit('showToast', '已经到列表底端，再次点击将回到列表顶端')
+      }
+      return
+    }
+    
+    // 原有的上下键处理逻辑
     isKeyboardNavigating.value = true
     if (keyboardTimer) clearTimeout(keyboardTimer)
     
-    const containerTop = containerRef.value?.scrollTop || 0
-    const containerHeight = containerRef.value?.clientHeight || 0
-    
     if (e.key === 'ArrowUp') {
       const nextIndex = Math.max(0, selectedIndex.value - 1)
       selectedIndex.value = nextIndex
       emit('select', { ...props.data[nextIndex], index: nextIndex })
       
       const itemTop = nextIndex * totalItemHeight.value
-      if (itemTop < containerTop && containerRef.value) {
+      if (itemTop < containerRef.value?.scrollTop && containerRef.value) {
         containerRef.value.scrollTop = itemTop
       }
     } else {
@@ -185,9 +232,9 @@ function handleKeyDown(e) {
       emit('select', { ...props.data[nextIndex], index: nextIndex })
       
       const itemBottom = (nextIndex + 1) * totalItemHeight.value
-      const scrollBottom = containerTop + containerHeight
+      const scrollBottom = (containerRef.value?.scrollTop || 0) + containerHeight.value
       if (itemBottom > scrollBottom && containerRef.value) {
-        containerRef.value.scrollTop = itemBottom - containerHeight
+        containerRef.value.scrollTop = itemBottom - containerHeight.value
       }
     }
     
@@ -197,7 +244,7 @@ function handleKeyDown(e) {
   }
 }
 
-// 确保选中项可见
+// 确保选项可见
 function ensureSelectedItemVisible() {
   if (!containerRef.value) return
   
@@ -259,6 +306,9 @@ onBeforeUnmount(() => {
   if (keyboardTimer) {
     clearTimeout(keyboardTimer)
   }
+  if (hoverTimer) {
+    clearTimeout(hoverTimer)
+  }
 })
 
 </script>