fix: address code review issues in danmaku components

components/DanmakuList.tsx

@@ -47,7 +47,7 @@ export default function DanmakuList({ danmakus, currentTime, visible, onToggle }
         <FlatList
           ref={flatListRef}
           data={visibleItems}
-          keyExtractor={(_, i) => String(i)}
+          keyExtractor={(item, i) => `${item.time}_${item.text}_${i}`}
           style={styles.list}
           renderItem={({ item }) => (
             <Text

components/DanmakuOverlay.tsx

@@ -28,6 +28,10 @@ export default function DanmakuOverlay({ danmakus, currentTime, screenWidth, scr
   const activated = useRef<Set<string>>(new Set());
   const prevTimeRef = useRef<number>(currentTime);
   const idCounter = useRef(0);
+  const mountedRef = useRef(true);
+  useEffect(() => {
+    return () => { mountedRef.current = false; };
+  }, []);
 
   const pickLane = useCallback((): number | null => {
     const now = Date.now();
@@ -37,6 +41,12 @@ export default function DanmakuOverlay({ danmakus, currentTime, screenWidth, scr
     return null;
   }, []);
 
+  useEffect(() => {
+    activated.current.clear();
+    laneAvailAt.current.fill(0);
+    setActiveDanmakus([]);
+  }, [danmakus]);
+
   useEffect(() => {
     if (!visible) return;
 
@@ -63,9 +73,9 @@ export default function DanmakuOverlay({ danmakus, currentTime, screenWidth, scr
 
     const newItems: ActiveDanmaku[] = [];
 
+    if (activated.current.size > 200) activated.current.clear(); // prevent memory leak
     for (const item of candidates) {
       const key = `${item.time}_${item.text}`;
-      if (activated.current.size > 200) activated.current.clear(); // prevent memory leak
       activated.current.add(key);
 
       if (item.mode === 1) {
@@ -94,7 +104,7 @@ export default function DanmakuOverlay({ danmakus, currentTime, screenWidth, scr
           duration,
           useNativeDriver: true,
         }).start(() => {
-          setActiveDanmakus(prev => prev.filter(d => d.id !== id));
+          if (mountedRef.current) setActiveDanmakus(prev => prev.filter(d => d.id !== id));
         });
       } else {
         // Fixed danmaku (mode 4 = bottom, mode 5 = top)
@@ -106,7 +116,7 @@ export default function DanmakuOverlay({ danmakus, currentTime, screenWidth, scr
           Animated.delay(2000),
           Animated.timing(opacity, { toValue: 0, duration: 500, useNativeDriver: true }),
         ]).start(() => {
-          setActiveDanmakus(prev => prev.filter(d => d.id !== id));
+          if (mountedRef.current) setActiveDanmakus(prev => prev.filter(d => d.id !== id));
         });
       }
     }

components/NativeVideoPlayer.tsx

@@ -9,7 +9,7 @@ import { Ionicons } from '@expo/vector-icons';
 import type { PlayUrlResponse, VideoShotData, DanmakuItem } from '../services/types';
 import { buildDashMpdUri } from '../utils/dash';
 import { getHeatmap, getVideoShot } from '../services/bilibili';
-import { DanmakuOverlay } from './DanmakuOverlay';
+import DanmakuOverlay from './DanmakuOverlay';
 
 const BAR_H = 3;
 const BALL = 12;