如何计算和检测PanResponder事件？

Question

我对动画和手势处理程序还很陌生。我正在阅读官方 React Native 动画中的文档，我发现了这段代码的片段，可以让你在蓝框周围移动。

import React, { useRef } from "react";
import { Animated, View, StyleSheet, PanResponder, Text } from "react-native";

const App = () => {
  const pan = useRef(new Animated.ValueXY()).current;
  const panResponder = useRef(
    PanResponder.create({
      onMoveShouldSetPanResponder: () => true,
      onPanResponderMove: Animated.event([
        null,
        { dx: pan.x, dy: pan.y }
      ]),
      onPanResponderRelease: () => {
        Animated.spring(pan, { toValue: { x: 0, y: 0 } }).start();
      }
    })
  ).current;

  return (
    <View style={styles.container}>
      <Text style={styles.titleText}>Drag & Release this box!</Text>
      <Animated.View
        style={{
          transform: [{ translateX: pan.x }, { translateY: pan.y }]
        }}
        {...panResponder.panHandlers}
      >
        <View style={styles.box} />
      </Animated.View>
    </View>
  );
}

const styles = StyleSheet.create({
  container: {
    flex: 1,
    alignItems: "center",
    justifyContent: "center"
  },
  titleText: {
    fontSize: 14,
    lineHeight: 24,
    fontWeight: "bold"
  },
  box: {
    height: 150,
    width: 150,
    backgroundColor: "blue",
    borderRadius: 5
  }
});

export default App;

但是，我想 console.log 或者在 panresponder 移动时做一些计算，所以我尝试修改我的 opPanResponderMove 但蓝框不再移动。我想知道为什么？

我修改的代码：

onPanResponderMove: (event, gestureState) => {
        console.log(event);
        console.log(gestureState);
        Animated.event([
            null,
            { dx: pan.x, dy: pan.y }
          ])
      },

Answer 1

你的问题有问题here

据说

Reason was because Animation.event() only generates the function which is used from onPanResponderMove, it also needs the default arguments evt, gestureState

这是解决方法：

onPanResponderMove: (event, gestureState) => {
        console.log(event);
        console.log(gestureState);
        return Animated.event([
            null,
            { dx: pan.x, dy: pan.y }
          ])(event,gestureState);
      },

如何计算和检测PanResponder事件？

How to calculate and detect PanResponder event?

animation

react-native