react-native-animations

React Native 动画技能

学习如何使用 Reanimated 3、Gesture Handler 和布局动画实现高性能动画。

前提条件

• React Native 基础知识
• 了解 JavaScript 闭包
• 熟悉变换和样式

学习目标

完成此技能后，你将能够：

• 使用 Reanimated 创建流畅的 60fps 动画
• 使用 Gesture Handler 处理复杂手势
• 实现布局进入和退出动画
• 优化动画性能
• 将手势与动画结合使用

---

涵盖主题

1. 安装

npm install react-native-reanimated react-native-gesture-handler

# babel.config.js
module.exports = {
  plugins: ['react-native-reanimated/plugin'],
};

2. Reanimated 基础知识

import Animated, {
  useSharedValue,
  useAnimatedStyle,
  withSpring,
} from 'react-native-reanimated';

function AnimatedBox() {
  const scale = useSharedValue(1);

  const animatedStyle = useAnimatedStyle(() => ({
    transform: [{ scale: scale.value }],
  }));

  const handlePress = () => {
    scale.value = withSpring(scale.value === 1 ? 1.5 : 1);
  };

  return (
    <Pressable onPress={handlePress}>
      <Animated.View style={[styles.box, animatedStyle]} />
    </Pressable>
  );
}

3. Gesture Handler

import { Gesture, GestureDetector } from 'react-native-gesture-handler';

function DraggableBox() {
  const translateX = useSharedValue(0);
  const translateY = useSharedValue(0);

  const pan = Gesture.Pan()
    .onUpdate((e) => {
      translateX.value = e.translationX;
      translateY.value = e.translationY;
    })
    .onEnd(() => {
      translateX.value = withSpring(0);
      translateY.value = withSpring(0);
    });

  const style = useAnimatedStyle(() => ({
    transform: [
      { translateX: translateX.value },
      { translateY: translateY.value },
    ],
  }));

  return (
    <GestureDetector gesture={pan}>
      <Animated.View style={[styles.box, style]} />
    </GestureDetector>
  );
}

4. 布局动画

import Animated, { FadeIn, FadeOut, Layout } from 'react-native-reanimated';

function AnimatedList({ items }) {
  return (
    <Animated.View layout={Layout.springify()}>
      {items.map((item) => (
        <Animated.View
          key={item.id}
          entering={FadeIn}
          exiting={FadeOut}
          layout={Layout.springify()}
        >
          <Text>{item.title}</Text>
        </Animated.View>
      ))}
    </Animated.View>
  );
}

5. 动画时序

函数	使用场景
withTiming	线性动画，时长可控
withSpring	自然的、基于物理效果的动画
withDecay	基于惯性的动画（甩动）
withSequence	按顺序播放多个动画
withRepeat	循环播放动画

---

快速入门示例

import Animated, {
  useSharedValue,
  useAnimatedStyle,
  withSpring,
  interpolate,
} from 'react-native-reanimated';
import { Gesture, GestureDetector } from 'react-native-gesture-handler';

function SwipeCard() {
  const translateX = useSharedValue(0);

  const gesture = Gesture.Pan()
    .onUpdate((e) => { translateX.value = e.translationX; })
    .onEnd(() => { translateX.value = withSpring(0); });

  const style = useAnimatedStyle(() => ({
    transform: [
      { translateX: translateX.value },
      { rotate: `${interpolate(translateX.value, [-200, 200], [-15, 15])}deg` },
    ],
  }));

  return (
    <GestureDetector gesture={gesture}>
      <Animated.View style={[styles.card, style]} />
    </GestureDetector>
  );
}

---

常见错误与解决方案

错误	原因	解决方案
"Attempted to call from worklet"	缺少 runOnJS	使用 runOnJS() 包装
动画未运行	缺少 'worklet'	添加 'worklet' 指令
手势不起作用	缺少根视图	添加 GestureHandlerRootView

---

验证清单

• 动画以 60fps 运行
• 手势响应流畅
• 低端设备上没有掉帧
• 布局动画不会造成卡顿

---

用法

Skill("react-native-animations")

绑定的 Agent：05-react-native-animation