javascript - 在滚动 React Native Animated 上做动画但闪烁

Question

在我的 React native 应用程序中，我试图为 View 的不透明度设置动画。当我滚动时，我看到动画完成了工作，但它同时闪烁。我不知道为什么。

视频示例:https://cdn.discordapp.com/attachments/102861040538120192/560165613092339734/video.mov

这是我写的代码

const Scrollable = () => {
  const largeHeaderSize = useState({
    height: 0,
    y: 0
  });

  const animatedValueScrollY = new Animated.Value(largeHeaderSize.height);
  const [scrollY, setScrollY] = useState(0);

  const headerOpacity = animatedValueScrollY.interpolate({
    inputRange: [0, largeHeaderSize.height],
    outputRange: [1, 0],
    extrapolate: "clamp"
  });

  return (
    <SafeAreaView>
      <Animated.View
        style={{
        borderBottomWidth:
          scrollY >= largeHeaderSize.height ? StyleSheet.hairlineWidth : 0
      }}>
        <View>
          <Animated.View style={{ zIndex: 1, opacity: headerOpacity }}>
            <Text>Title</Text>
          </Animated.View>
        </View>
      </Animated.View>
      <Animated.ScrollView
        onScroll={Animated.event(
          [{ nativeEvent: { contentOffset: { y: animatedValueScrollY } } }],
          {
            useNativeDriver: true,
            listener: event => setScrollY(event.nativeEvent.contentOffset.y)
          }
        )}
        scrollEventThrottle={16}
        contentInset={{
          top: 0,
          bottom: 50
        }}
        contentOffset={{
          y: 0
        }}
      />
    </SafeAreaView>
  );
};

我该如何解决？

Answer 1

解决方案是像这样使用 useRef 钩子(Hook):

const animatedValueScrollY = useRef(new Animated.Value(0))

const headerOpacity = animatedValueScrollY.current.interpolate({
   inputRange: [0, largeHeaderSize.height],
   outputRange: [1, 0],
   extrapolate: 'clamp'
});