首页 > 解决方案 > React 原生动画进度条

问题描述

我正在尝试为我的 react-native 项目构建一个进度条它应该是一个可以在很多地方使用的通用组件。请看我的代码:

进度条 tsx:

import React, { useEffect } from 'react'
import { Animated, StyleProp, StyleSheet, View, ViewStyle } from 'react-native'

interface Props {
  total: number
  progress: number
  color?: string
  backgroundColor?: string
  height?: number
  style?: StyleProp<ViewStyle>
  animDelay?: number
  animDuration?: number
  testID?: string
}

const ProgressBar = ({
  color,
  backgroundColor,
  style,
  height,
  animDelay,
  animDuration,
  total,
  progress,
  testID = 'progress-bar',
}: Props): JSX.Element => {
  const minWidthValue = 5.4
  const percentage = total && progress ? Math.min(progress, total) / total : 0
  const minDisplayWidth =
    percentage > 0 && percentage < minWidthValue ? minWidthValue : percentage
  const barWidth = `${Math.max(minDisplayWidth, Math.floor(percentage * 100))}%`

  useEffect(() => {
    const animationValue = new Animated.Value(0)
    Animated.timing(animationValue, {
      toValue: progress,
      delay: animDelay,
      duration: animDuration,
      useNativeDriver: true,
    }).start();
  }, []);

  return (
    <View
      testID={testID}
      style={[
        styles.container,
        height ? { height } : undefined,
        backgroundColor ? { backgroundColor } : undefined,
        style,
      ]}>
      <Animated.View
        style={[
          styles.bar,
          {
            backgroundColor: color,
            width: barWidth,
          },
        ]}
      />
    </View>
  )
}

export default ProgressBar

const BORDER_RADIUS = 15

const styles = StyleSheet.create({
  bar: {
    borderRadius: BORDER_RADIUS,
    height: '100%',
  },
  container: {
    borderRadius: BORDER_RADIUS,
    flexDirection: 'row',
    height: 30,
    overflow: 'hidden',
    width: '100%',
  },
})

还有用法的例子,在 home.tsx 上说:

<ProgressBarWrapper total={100} progress={50} testID='test-id-test-1' />

所以会发生什么,总长度(100%),我希望动画从 0 移动到 50 开始时,当这个组件加载时

在此处输入图像描述

使用上面的代码,我只得到一个静态栏,根本不动。有人能指出我做错了什么吗?示例代码会很有帮助 干杯

编辑:

我已经更新了代码

useNativeDriver

interpolation在此处使用“clamp”来避免振荡

但是,动画仍然没有移动/工作,想知道对此有何建议。谢谢

const ProgressBarInternal = ({
  color,
  backgroundColor,
  style,
  height,
  animDelay,
  animDuration,
  total,
  progress,
  testID = 'progress-bar',
  borderRadius,
  containerHeight,
  onAnimationDidEnd,
}: Props): JSX.Element => {
  const minWidthValue = 5.4
  const percentage = total && progress ? Math.min(progress, total) / total : 0
  const minDisplayWidth =
    percentage > 0 && percentage < minWidthValue ? minWidthValue : percentage
  const progressingBarWidthPercentage = `${Math.max(minDisplayWidth, Math.floor(percentage * 100))}%`

  const animatingProgressBar = useRef(new Animated.Value(0))
  useEffect(() => {
    Animated.timing(animatingProgressBar.current, {
      toValue: 0,
      delay: animDelay,
      duration: animDuration,
      useNativeDriver: true,
    }).start()
  }, []
  );

  return (
    <View
      testID={testID}
      style={...}>
      <Animated.View        
        style={[
          styles.bar,
          { borderRadius: borderRadius },
          {
            backgroundColor: color,
            width: progressingBarWidthPercentage,
          },
          {
            transform: [
              {
                translateX: animatingProgressBar.current.interpolate({
                  inputRange: [1, 100],
                  outputRange: ["0%", "100%"],
                  extrapolate: "clamp"
                }),
              },
            ],
          },
        ]}
      />
    </View>
  )
}

标签: javascriptreactjstypescriptreact-nativeanimation

解决方案


当 useNativeDriver 设置为 true 时,我遇到了类似的行为。

将 useNativeDriver 更改为 false 可能会解决您的问题

这也是我如何实现动画宽度的示例:

const barWidth = useRef(new Animated.Value(0)).current;
const progressPercent = barWidth.interpolate({
    inputRange: [0, 100],
    outputRange: ["0%", `100%`],
});
useEffect(() => {
    animatedController.setValue(0)

    Animated.timing(barWidth, {
        duration: 5000,
        toValue: 100,
        useNativeDriver: false
    }).start();
}, [])

return (
<View style={...}>
  <Animated.View
    style={[
      styles.bar,
      {
        backgroundColor: color,
        width: progressPercent,
      }
   ]}
  />
</View>

)


推荐阅读