我正在尝试使用 useEffect 找到 ComponentWillMount 方法的替代品。但是 panresponder 变量不是在初始渲染之前创建的。谁能告诉我我在这里做的任何错误?没有 useEffect,页面将被渲染。手势未被捕获。
const makeup = () => {
useEffect(() => {
console.log('I am about to render!');
const panResponder = useRef(
PanResponder.create({
onStartShouldSetPanResponder: (e, gestureState) => true,
onPanResponderMove: (e, gestureState) => {....},
onPanResponderRelease: (e, gestaureState) => {....}
}));
},[]);
return ARTICLES.map((item, i) => {
console.log("Makeup i:"+i+" item:"+item);
if (i === index.currentIndex - 1) {
return (
<Animated.View
key={item.id}
style={swipeCardPosition.getLayout()}
{...panResponder.panHandlers}
>
</Animated.View>
);
}
if (i < index.currentIndex) {
return null;
}
return (
<Animated.View
key={item.id}
style={index.currentIndex === i ? position.getLayout() : null}
{...(index.currentIndex === i
? { ...panResponder.panHandlers }
: null)}
>
</Animated.View>
);
}).reverse();
};
[Error on execution][1]
[1]: https://i.stack.imgur.com/sls5E.png