2

滚动列表时为视图的高度设置动画非常缓慢且不稳定，它适用于 IOS，但不适用于 Android：

import * as React from "react";
import { StyleSheet, Text } from "react-native";
import Animated from "react-native-reanimated";
const { Value, View, ScrollView, interpolate, Extrapolate } = Animated;
const styles = StyleSheet.create({
  container: {
    flex: 1,
    backgroundColor: "black"
  },
  listView: {
    flex: 1
  }
});

const IMAGE_MIN_HEIGHT = 300;

export default () => {
  const animation = new Value(0);

  const height = interpolate(animation, {
    inputRange: [0, 125],
    outputRange: [IMAGE_MIN_HEIGHT, 125],
    extrapolate: Extrapolate.CLAMP
  });

  return (
    <View style={styles.container}>
      <View
        style={{
          backgroundColor: "red",
          height: height,
          width: "100%"
        }}
      ></View>
      <ScrollView
        onScroll={Animated.event([
          {
            nativeEvent: {
              contentOffset: {
                y: animation
              }
            }
          }
        ])}
        scrollEventThrottle={1}
        style={[styles.listView]}
      >
        {[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0].map((elem, index) => (
          <View
            style={{ width: "100%", height: 100, marginBottom: 20 }}
            key={index}
          >
            <Text style={{ color: "white", fontSize: 30 }}>{elem}</Text>
          </View>
        ))}
      </ScrollView>
    </View>
  );
};

有什么办法可以让它更顺畅吗？

4

2 回答 2

4

解决方案是将标题位置设置为绝对，我不知道为什么，但它工作正常：

import * as React from "react";
import { StyleSheet, Text, Platform } from "react-native";
import Animated from "react-native-reanimated";
const { Value, View, ScrollView, interpolate, Extrapolate } = Animated;
const styles = StyleSheet.create({
  container: {
    flex: 1,
    backgroundColor: "black"
  },
  listView: {
    flex: 1
  }
});

const IMAGE_MIN_HEIGHT = 300;

export default () => {
  const animation = new Value(0);

  const height = interpolate(animation, {
    inputRange: [0, 125],
    outputRange: [IMAGE_MIN_HEIGHT, 125],
    extrapolate: Extrapolate.CLAMP
  });

  return (
    <View style={styles.container}>
      <ScrollView
        contentContainerStyle={{ paddingTop: IMAGE_MIN_HEIGHT }}
        onScroll={Animated.event([
          {
            nativeEvent: {
              contentOffset: {
                y: animation
              }
            }
          }
        ])}
        scrollEventThrottle={1}
        style={[styles.listView]}
      >
        {[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0].map((elem, index) => (
          <View
            style={{ width: "100%", height: 100, marginBottom: 20 }}
            key={index}
          >
            <Text style={{ color: "white", fontSize: 30 }}>{elem}</Text>
          </View>
        ))}
      </ScrollView>

      <View
        style={{
          backgroundColor: "red",
          height: height,
          width: "100%",
          position: "absolute",
          top: Platform.OS == "ios" ? 20 : 0,
          left: 0,
          right: 0
        }}
      ></View>
    </View>
  );
};
于 2020-03-30T01:03:52.783 回答
0

尝试使用 Android 的 NativeDriver。

此外，为了获得更好的性能，您应该在此处使用FlatList或SectionList而不是 ScrollView。

 <Animated.ScrollView
    onScroll={Animated.event([
      {
        nativeEvent: {
          contentOffset: {
            y: animation
          }
        }
      }
    ], 
     { useNativeDriver: true } // Add this line
    )}        
    scrollEventThrottle={1}
    style={[styles.listView]}
  >
    //
  </Animated.ScrollView>

更多详情，请看这里

于 2020-03-29T23:58:32.673 回答