refactor(HomeScreen): simplify capsule visibility logic and improve list rendering

- Removed unnecessary state and logic related to capsule visibility based on scroll position, streamlining the component's functionality.
- Adjusted FlatList properties to enhance rendering performance and layout consistency.
- Updated styles for the list header to ensure full-width display, improving the overall UI experience.

src/screens/home/HomeScreen.tsx

@@ -9,9 +9,7 @@ import {
   View,
   FlatList,
   ScrollView,
-  LayoutAnimation,
   Platform,
-  UIManager,
   StyleSheet,
   RefreshControl,
   StatusBar,
@@ -48,7 +46,6 @@ const SWIPE_COOLDOWN_MS = 300;
 const MOBILE_TAB_BAR_HEIGHT = 64;
 const MOBILE_TAB_FLOATING_MARGIN = 12;
 const MOBILE_FAB_GAP = 12;
-const CAPSULE_HIDE_THRESHOLD = 24;
 
 type ViewMode = 'list' | 'grid';
 type PostType = 'follow' | 'hot' | 'latest';
@@ -77,7 +74,6 @@ export const HomeScreen: React.FC = () => {
   const [viewMode, setViewMode] = useState<ViewMode>('list');
   const [latestCapsules, setLatestCapsules] = useState<LatestCapsule[]>([{ id: '', name: '全部' }]);
   const [activeCapsuleId, setActiveCapsuleId] = useState('');
-  const [showLatestCapsules, setShowLatestCapsules] = useState(true);
   
   // 图片查看器状态
   const [showImageViewer, setShowImageViewer] = useState(false);
@@ -94,15 +90,8 @@ export const HomeScreen: React.FC = () => {
   const postIdsRef = useRef<Set<string>>(new Set());
   const lastSwipeAtRef = useRef(0);
   
-  // 网格模式滚动位置检测
-  const gridScrollYRef = useRef(0);
-  const listScrollYRef = useRef(0);
   const isLoadingMoreRef = useRef(false);
 
-  if (Platform.OS === 'android' && UIManager.setLayoutAnimationEnabledExperimental) {
-    UIManager.setLayoutAnimationEnabledExperimental(true);
-  }
-
   // 构建一个以 postId 为 key 的 map，用于快速查找
   const postsMap = useMemo(() => {
     const map = new Map<string, Post>();
@@ -125,21 +114,6 @@ export const HomeScreen: React.FC = () => {
   const isLatestTab = activeIndex === 1;
   const currentChannelId = isLatestTab && activeCapsuleId ? activeCapsuleId : undefined;
 
-  const updateCapsuleVisibilityByScroll = useCallback((nextY: number, previousY: number) => {
-    if (!isLatestTab) return;
-    const delta = nextY - previousY;
-    const isScrollingDown = delta > CAPSULE_HIDE_THRESHOLD;
-    const isScrollingUp = delta < -CAPSULE_HIDE_THRESHOLD;
-
-    if (isScrollingDown && showLatestCapsules) {
-      LayoutAnimation.configureNext(LayoutAnimation.Presets.easeInEaseOut);
-      setShowLatestCapsules(false);
-    } else if (isScrollingUp && !showLatestCapsules) {
-      LayoutAnimation.configureNext(LayoutAnimation.Presets.easeInEaseOut);
-      setShowLatestCapsules(true);
-    }
-  }, [isLatestTab, showLatestCapsules]);
-
   // 使用差异更新 Hook 获取帖子列表
   const listKey = useMemo(
     () => `home_${getPostType()}_${currentChannelId || 'all'}`,
@@ -196,9 +170,7 @@ export const HomeScreen: React.FC = () => {
     if (scrollY + visibleHeight >= contentHeight - 200) {
       loadMore();
     }
-    updateCapsuleVisibilityByScroll(scrollY, gridScrollYRef.current);
-    gridScrollYRef.current = scrollY;
-  }, [loadMore, updateCapsuleVisibilityByScroll]);
+  }, [loadMore]);
 
   // 刷新方法 - 先获取正确类型的帖子，再刷新
   const refresh = useCallback(async () => {
@@ -303,12 +275,6 @@ export const HomeScreen: React.FC = () => {
     setActiveIndex(nextIndex);
   }, [activeIndex]);
 
-  useEffect(() => {
-    setShowLatestCapsules(true);
-    listScrollYRef.current = 0;
-    gridScrollYRef.current = 0;
-  }, [activeIndex]);
-
   useEffect(() => {
     const loadChannels = async () => {
       const list = await channelService.list();
@@ -481,7 +447,7 @@ export const HomeScreen: React.FC = () => {
   };
 
   const renderLatestCapsules = () => {
-    if (!isLatestTab || !showLatestCapsules) {
+    if (!isLatestTab) {
       return null;
     }
 
@@ -716,6 +682,7 @@ export const HomeScreen: React.FC = () => {
         renderItem={renderPostList}
         keyExtractor={keyExtractor}
         ListHeaderComponent={renderLatestCapsules()}
+        ListHeaderComponentStyle={styles.listHeader}
         contentContainerStyle={[
           styles.listContent,
           {
@@ -735,11 +702,6 @@ export const HomeScreen: React.FC = () => {
         }
         onEndReached={loadMore}
         onEndReachedThreshold={0.3}
-        onScroll={(event) => {
-          const nextY = event.nativeEvent.contentOffset.y;
-          updateCapsuleVisibilityByScroll(nextY, listScrollYRef.current);
-          listScrollYRef.current = nextY;
-        }}
         scrollEventThrottle={16}
         ListEmptyComponent={renderEmpty}
         ListFooterComponent={isLoadingMore ? <Loading size="sm" /> : null}
@@ -747,7 +709,7 @@ export const HomeScreen: React.FC = () => {
         maxToRenderPerBatch={8}
         updateCellsBatchingPeriod={60}
         windowSize={7}
-        removeClippedSubviews
+        removeClippedSubviews={false}
       />
     );
   };
@@ -918,6 +880,9 @@ const styles = StyleSheet.create({
   listContent: {
     flexGrow: 1,
   },
+  listHeader: {
+    width: '100%',
+  },
   contentContainer: {
     flex: 1,
   },