reactjs - 如何从react组件类中使用react-spring

Question

我正在尝试将 react-spring 动画库导入到基于 React 组件类的 ReactJS 应用程序中。

似乎新的(截至 2019 年)React Hooks 使一些集成变得更加困惑。

这就是为什么我问如何使用 react-spring ，它又使用 React hooks，在 ReactJS 应用程序中使用类。

无法正常工作的代码如下所示:

import React from 'react';
import { useSpring, animated, interpolate } from 'react-spring'


export default class TestAnimation extends React.Component {

    constructor(props) {
        super(props);

        const { o, xyz, color } = useSpring({
            from: { o: 0, xyz: [0, 0, 0], color: 'red' },
            o: 1,
            xyz: [10, 20, 5],
            color: 'green'
        });

        this.aniText = <animated.div
            style={{
                // If you can, use plain animated values like always, ...
                // You would do that in all cases where values "just fit"
                color,
                // Unless you need to interpolate them
                background: o.interpolate(o => `rgba(210, 57, 77, ${o})`),
                // Which works with arrays as well
                transform: xyz.interpolate((x, y, z) => `translate3d(${x}px, ${y}px, ${z}px)`),
                // If you want to combine multiple values use the "interpolate" helper
                border: interpolate([o, color], (o, c) => `${o * 10}px solid ${c}`),
                // You can also form ranges, even chain multiple interpolations
                padding: o.interpolate({ range: [0, 0.5, 1], output: [0, 0, 10] }).interpolate(o => `${o}%`),
                // Interpolating strings (like up-front) through ranges is allowed ...
                borderColor: o.interpolate({ range: [0, 1], output: ['red', '#ffaabb'] }),
                // There's also a shortcut for plain, optionless ranges ...
                opacity: o.interpolate([0.1, 0.2, 0.6, 1], [1, 0.1, 0.5, 1])
            }}
        >
            {o.interpolate(n => n.toFixed(2)) /* innerText interpolation ... */}

        </animated.div>
    };


    render() {
        return <div>
            {this.aniText}
        </div>;
    }
}

这会导致此错误:

Invalid hook call. Hooks can only be called inside of the body of a function component. This could happen for one of the following reasons:
1. You might have mismatching versions of React and the renderer (such as React DOM)
2. You might be breaking the Rules of Hooks
3. You might have more than one copy of React in the same app

Answer 1

您不能在类组件内使用钩子(Hook)。因此，您可以将动画组件拆分为自己的功能组件，如下所示:

import React from 'react';
import { useSpring, animated, interpolate } from 'react-spring'

const AniText = ()=> {
  const { o, xyz, color } = useSpring({
    from: { o: 0, xyz: [0, 0, 0], color: 'red' },
    o: 1,
    xyz: [10, 20, 5],
    color: 'green'
  });

  return (<animated.div
    style={{
        // If you can, use plain animated values like always, ...
        // You would do that in all cases where values "just fit"
        color,
        // Unless you need to interpolate them
        background: o.interpolate(o => `rgba(210, 57, 77, ${o})`),
        // Which works with arrays as well
        transform: xyz.interpolate((x, y, z) => `translate3d(${x}px, ${y}px, ${z}px)`),
        // If you want to combine multiple values use the "interpolate" helper
        border: interpolate([o, color], (o, c) => `${o * 10}px solid ${c}`),
        // You can also form ranges, even chain multiple interpolations
        padding: o.interpolate({ range: [0, 0.5, 1], output: [0, 0, 10] }).interpolate(o => `${o}%`),
        // Interpolating strings (like up-front) through ranges is allowed ...
        borderColor: o.interpolate({ range: [0, 1], output: ['red', '#ffaabb'] }),
        // There's also a shortcut for plain, optionless ranges ...
        opacity: o.interpolate([0.1, 0.2, 0.6, 1], [1, 0.1, 0.5, 1])
    }}
  >
    {o.interpolate(n => n.toFixed(2)) /* innerText interpolation ... */}

  </animated.div>)

}

export default class TestAnimation extends React.Component {

    constructor(props) {
        super(props);
    }

    render() {
        return <div>
            <AniText />
        </div>;
    }
}

或者，如果你想坚持使用类组件，react-spring exports a render-props API同样，这在任何 React 组件、类或其他内部都是完全有效的:

import React from "react";
import { Spring, animated, interpolate } from "react-spring/renderprops";

export default class TestAnimation extends React.Component {
  constructor(props) {
    super(props);
  }

  render() {
    return (
      <div>
        <Spring
          native
          from={{ o: 0, xyz: [0, 0, 0], color: "red" }}
          to={{ o: 1, xyz: [10, 20, 5], color: "green" }}
        >
          {({ o, xyz, color }) => (
            <animated.div
              style={{
                // If you can, use plain animated values like always, ...
                // You would do that in all cases where values "just fit"
                color,
                // Unless you need to interpolate them
                background: o.interpolate(o => `rgba(210, 57, 77, ${o})`),
                // Which works with arrays as well
                transform: xyz.interpolate(
                  (x, y, z) => `translate3d(${x}px, ${y}px, ${z}px)`
                ),
                // If you want to combine multiple values use the "interpolate" helper
                border: interpolate(
                  [o, color],
                  (o, c) => `${o * 10}px solid ${c}`
                ),
                // You can also form ranges, even chain multiple interpolations
                padding: o
                  .interpolate({ range: [0, 0.5, 1], output: [0, 0, 10] })
                  .interpolate(o => `${o}%`),
                // There's also a shortcut for plain, optionless ranges ...
                opacity: o.interpolate([0.1, 0.2, 0.6, 1], [1, 0.1, 0.5, 1])
              }}
            >
              {// Finally, this is how you interpolate innerText
              o.interpolate(n => n.toFixed(2))}
            </animated.div>
          )}
        </Spring>
      </div>
    );
  }
}

这是一个 codeandbox，并排包含两个解决方案: https://codesandbox.io/s/8ynxyowzk0