更新前端：实现无限滚动加载及前后日期可用性检测

webapp/src/views/Home.vue

@@ -173,13 +173,18 @@
             <span>加载中...</span>
           </div>
           
-          <button 
+          <div 
             v-else-if="hasMore"
-            @click="loadMore"
-            class="px-8 py-3 bg-white/10 backdrop-blur-md text-white rounded-lg font-semibold hover:bg-white/20 transition-all border border-white/30"
+            ref="loadMoreTrigger"
+            class="inline-block"
           >
-            加载更多
-          </button>
+            <button 
+              @click="loadMore"
+              class="px-8 py-3 bg-white/10 backdrop-blur-md text-white rounded-lg font-semibold hover:bg-white/20 transition-all border border-white/30"
+            >
+              加载更多
+            </button>
+          </div>
 
           <p v-else class="text-white/40">
             已加载全部图片
@@ -246,8 +251,8 @@ const router = useRouter()
 // 获取今日图片
 const { image: todayImage, loading: todayLoading } = useTodayImage()
 
-// 获取图片列表（使用服务端分页和筛选）
-const { images, loading, hasMore, loadMore, filterByMonth } = useImageList(30)
+// 获取图片列表（使用服务端分页和筛选，每页15张）
+const { images, loading, hasMore, loadMore, filterByMonth } = useImageList(15)
 
 // 筛选相关状态
 const selectedYear = ref('')
@@ -258,6 +263,10 @@ const imageRefs = ref<(HTMLElement | null)[]>([])
 const imageVisibility = ref<boolean[]>([])
 let observer: IntersectionObserver | null = null
 
+// 无限滚动加载
+const loadMoreTrigger = ref<HTMLElement | null>(null)
+let loadMoreObserver: IntersectionObserver | null = null
+
 // 计算可用的年份列表（基于当前日期生成，从2020年到当前年份）
 const availableYears = computed(() => {
   const currentYear = new Date().getFullYear()
@@ -360,16 +369,6 @@ const setupObserver = () => {
   })
 }
 
-// 初始化懒加载状态
-onMounted(() => {
-  // 初始化时设置
-  if (images.value.length > 0) {
-    imageVisibility.value = new Array(images.value.length).fill(false)
-    setTimeout(() => {
-      setupObserver()
-    }, 100)
-  }
-})
 
 // 监听 images 变化，动态更新 imageVisibility
 watch(() => images.value.length, (newLength, oldLength) => {
@@ -399,11 +398,51 @@ watch(() => images.value.length, (newLength, oldLength) => {
   }
 })
 
+// 设置无限滚动 Observer
+const setupLoadMoreObserver = () => {
+  if (loadMoreObserver) {
+    loadMoreObserver.disconnect()
+  }
+  
+  loadMoreObserver = new IntersectionObserver(
+    (entries) => {
+      entries.forEach(entry => {
+        if (entry.isIntersecting && !loading.value && hasMore.value) {
+          loadMore()
+        }
+      })
+    },
+    {
+      root: null,
+      rootMargin: '100px',
+      threshold: 0.1
+    }
+  )
+  
+  if (loadMoreTrigger.value) {
+    loadMoreObserver.observe(loadMoreTrigger.value)
+  }
+}
+
+// 初始化时设置无限滚动
+onMounted(() => {
+  if (images.value.length > 0) {
+    imageVisibility.value = new Array(images.value.length).fill(false)
+    setTimeout(() => {
+      setupObserver()
+      setupLoadMoreObserver()
+    }, 100)
+  }
+})
+
 // 清理
 onUnmounted(() => {
   if (observer) {
     observer.disconnect()
   }
+  if (loadMoreObserver) {
+    loadMoreObserver.disconnect()
+  }
 })
 
 // 格式化日期

webapp/src/views/ImageView.vue

@@ -89,7 +89,7 @@
           <div class="flex items-center gap-4">
             <button 
               @click="previousDay"
-              :disabled="navigating"
+              :disabled="navigating || !hasPreviousDay"
               class="flex items-center gap-2 px-4 py-2 bg-white/10 backdrop-blur-md text-white rounded-lg hover:bg-white/20 transition-all disabled:opacity-50 disabled:cursor-not-allowed"
             >
               <svg class="w-5 h-5" fill="none" stroke="currentColor" viewBox="0 0 24 24">
@@ -100,7 +100,7 @@
 
             <button 
               @click="nextDay"
-              :disabled="navigating || isToday"
+              :disabled="navigating || !hasNextDay"
               class="flex items-center gap-2 px-4 py-2 bg-white/10 backdrop-blur-md text-white rounded-lg hover:bg-white/20 transition-all disabled:opacity-50 disabled:cursor-not-allowed"
             >
               <span class="hidden sm:inline">后一天</span>
@@ -141,7 +141,7 @@
 </template>
 
 <script setup lang="ts">
-import { ref, computed } from 'vue'
+import { ref } from 'vue'
 import { useRoute, useRouter } from 'vue-router'
 import { useImageByDate } from '@/composables/useImages'
 import { bingPaperApi } from '@/lib/api-service'
@@ -153,6 +153,11 @@ const currentDate = ref(route.params.date as string)
 const showInfo = ref(true)
 const navigating = ref(false)
 
+// 前后日期可用性
+const hasPreviousDay = ref(true)
+const hasNextDay = ref(true)
+const checkingDates = ref(false)
+
 // 拖动相关状态
 const infoPanel = ref<HTMLElement | null>(null)
 const infoPanelPos = ref({ x: 0, y: 0 })
@@ -230,9 +235,50 @@ const stopDrag = () => {
 // 使用 composable 获取图片数据（传递 ref，自动响应日期变化）
 const { image, loading, error } = useImageByDate(currentDate)
 
+// 检测指定日期是否有数据
+const checkDateAvailability = async (dateStr: string): Promise<boolean> => {
+  try {
+    await bingPaperApi.getImageMetaByDate(dateStr)
+    return true
+  } catch (e) {
+    return false
+  }
+}
+
+// 检测前后日期可用性
+const checkAdjacentDates = async () => {
+  if (checkingDates.value) return
+  
+  checkingDates.value = true
+  const date = new Date(currentDate.value)
+  
+  // 检测前一天
+  const prevDate = new Date(date)
+  prevDate.setDate(prevDate.getDate() - 1)
+  hasPreviousDay.value = await checkDateAvailability(prevDate.toISOString().split('T')[0])
+  
+  // 检测后一天（不能超过今天）
+  const nextDate = new Date(date)
+  nextDate.setDate(nextDate.getDate() + 1)
+  const today = new Date().toISOString().split('T')[0]
+  if (nextDate.toISOString().split('T')[0] > today) {
+    hasNextDay.value = false
+  } else {
+    hasNextDay.value = await checkDateAvailability(nextDate.toISOString().split('T')[0])
+  }
+  
+  checkingDates.value = false
+}
+
 // 初始化位置
 initPanelPosition()
 
+// 监听日期变化，检测前后日期可用性
+import { watch } from 'vue'
+watch(currentDate, () => {
+  checkAdjacentDates()
+}, { immediate: true })
+
 // 格式化日期
 const formatDate = (dateStr?: string) => {
   if (!dateStr) return ''
@@ -245,12 +291,6 @@ const formatDate = (dateStr?: string) => {
   })
 }
 
-// 判断是否是今天
-const isToday = computed(() => {
-  const today = new Date().toISOString().split('T')[0]
-  return currentDate.value === today
-})
-
 // 获取完整图片 URL
 const getFullImageUrl = () => {
   return bingPaperApi.getImageUrlByDate(currentDate.value, 'UHD', 'jpg')
@@ -265,7 +305,7 @@ const goBack = () => {
 
 // 前一天
 const previousDay = () => {
-  if (navigating.value) return
+  if (navigating.value || !hasPreviousDay.value) return
   
   navigating.value = true
   const date = new Date(currentDate.value)
@@ -282,7 +322,7 @@ const previousDay = () => {
 
 // 后一天
 const nextDay = () => {
-  if (navigating.value || isToday.value) return
+  if (navigating.value || !hasNextDay.value) return
   
   navigating.value = true
   const date = new Date(currentDate.value)
@@ -299,9 +339,9 @@ const nextDay = () => {
 
 // 键盘导航
 const handleKeydown = (e: KeyboardEvent) => {
-  if (e.key === 'ArrowLeft') {
+  if (e.key === 'ArrowLeft' && hasPreviousDay.value) {
     previousDay()
-  } else if (e.key === 'ArrowRight' && !isToday.value) {
+  } else if (e.key === 'ArrowRight' && hasNextDay.value) {
     nextDay()
   } else if (e.key === 'Escape') {
     goBack()