修复虚拟列表组件的点击和键盘导航逻辑，确保在列表被冻结时不响应点击，并处理边界条件以避免错误的滚动行为。

src/components/VirtualList.vue

@@ -93,7 +93,7 @@ const handleSelect = (item) => {
 
 // 点击处理
 const handleClick = (item) => {
-  if (props.frozen) return  // 如果列表被冻<EFBFBD><EFBFBD>，不响应点击
+  if (props.frozen) return  // 如果列表被冻结，不响应点击
   handleSelect(item)  // 点击时同时触发选中
   emit('click', item)
 }
@@ -155,21 +155,28 @@ function handleKeyDown(e) {
   } else if (e.key === 'ArrowUp' || e.key === 'ArrowDown') {
     e.preventDefault()
     
+    const isFirstItem = selectedIndex.value === 0
+    const isLastItem = selectedIndex.value === props.data.length - 1
+    
+    // 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)) {
+      return
+    }
+    
     isKeyboardNavigating.value = true
     if (keyboardTimer) clearTimeout(keyboardTimer)
     
-    const containerTop = containerRef.value.scrollTop
-    const containerHeight = containerRef.value.clientHeight
+    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 })
       
-      // 使用与向下相同的逻辑，计算项目顶部位置
       const itemTop = nextIndex * totalItemHeight.value
-      
-      if (itemTop < containerTop) {
+      if (itemTop < containerTop && containerRef.value) {
         containerRef.value.scrollTop = itemTop
       }
     } else {
@@ -177,11 +184,9 @@ function handleKeyDown(e) {
       selectedIndex.value = nextIndex
       emit('select', { ...props.data[nextIndex], index: nextIndex })
       
-      // 计算项目底部位置
       const itemBottom = (nextIndex + 1) * totalItemHeight.value
       const scrollBottom = containerTop + containerHeight
-      
-      if (itemBottom > scrollBottom) {
+      if (itemBottom > scrollBottom && containerRef.value) {
         containerRef.value.scrollTop = itemBottom - containerHeight
       }
     }