如何在功能组件中使用 PanResponder？

Question

The official documentation and all the tutorials I found use PanResponder as a part of React Classes, but is there a way we can use it with functional components and hooks? I tried doing it as follows but it doesn't seem to work:-

const App = props => {
  const position = useRef(new Animated.ValueXY()).current;
  const panResponder = useRef(
    PanResponder.create({
      onStartShouldSetPanResponder: (evt, gestureState) => true,
      onPanResponderMove: (evt, gestureState) => {
        position.setValue({x: gestureState.dx, y: gestureState.dy});
      },
      onPanResponderRelease: (evt, gestureState) => {},
    }),
  ).current;

...

<Animated.View
            {...panResponder.panHandlers}
            style={[
              {transform: position.getTranslateTransform()},
              styles.appStyles,
            ]}>
...
</Animated.View>

Answer 1

found solution here: https://github.com/facebook/react-native/issues/25360#issuecomment-505241400

useMemo avoids recreating the PanResponder on every rerendering

then your code should look like this

const App = props => {
  const position = useRef(new Animated.ValueXY()).current;
  const panResponder = React.useMemo(() => PanResponder.create({
      onStartShouldSetPanResponder: (evt, gestureState) => true,
      onPanResponderMove: (evt, gestureState) => {
        position.setValue({x: gestureState.dx, y: gestureState.dy});
      },
      onPanResponderRelease: (evt, gestureState) => {},
    }), []);

...

<Animated.View
            {...panResponder.panHandlers}
            style={[
              {transform: position.getTranslateTransform()},
              styles.appStyles,
            ]}>
...
</Animated.View>

Answer 2

The official doc suggests using useRef()

https://reactnative.dev/docs/panresponder