为什么React-Transition-Group在路由更改时不调用componentWillEnter或componentWillLeave？

Question

我正在遵循此hackernoon指南https://hackernoon.com/animated-page-transitions-with-react-router-4-reacttransitiongroup-and-animated-1ca17bd97a1a ，以便在进入路线时将Enter动画留给我的react组件变化。 我显然已经修改了代码以适合我的网站，并决定不使用Animated而是仅使用纯CSS。 现在，我只是使用console.log语句测试代码，并且我注意到在路由更改时未调用componentWillEnter和componentWillLeave。 此外，componentWillAppear仅被调用一次。

以下是每个组件的相关代码，包括App.js和index.js：

动画包装器：

import React, {Component} from "react";
import styles from '../styles/AnimatedWrapper.css';

const AnimatedWrapper = WrappedComponent =>
  class AnimatedWrapper extends Component {
    componentWillAppear(cb) {
      console.log('componentWillAppear');
      cb();
    }
    componentWillEnter(cb) {
      console.log('componentWillEnter');
      cb();
    }
    componentWillLeave(cb) {
      console.log('componentWillLeave');
      cb();
    }
    render() {
      return (
        <div id="animated-wrapper" className={styles.animatedPageWrapper}>
          <WrappedComponent {...this.props}/>
        </div>
      );}
    };

export default AnimatedWrapper;

App.js：

import React, { Component } from 'react';
import { Route, Switch } from 'react-router-dom';
import TransitionGroup from "react-transition-group/TransitionGroup";

import Navbar from "./components/Navbar";
import Footer from "./components/Footer";
import Slider from "./components/Slider";
import ComingSoon from "./components/ComingSoon";

const firstChild = props => {
  const childrenArray = React.Children.toArray(props.children);
  return childrenArray[0] || null;
}

class App extends Component {
  render() {
    return (
      <div className="App">
        <Navbar />
        <Switch>
          <Route
            path="/coming-soon"
            children={({ match, ...rest }) => (
              <TransitionGroup component={firstChild}>
                {match && <ComingSoon {...rest} />}
              </TransitionGroup>
          )}/>
          <Route
             path="/"
             children={({ match, ...rest }) => (
               <TransitionGroup component={firstChild}>
                 {match && <Slider {...rest} />}
               </TransitionGroup>
          )}/>
        </Switch>
        <Footer />
      </div>
    );
  }
}

export default App;

index.js：

import React from 'react';
import ReactDOM from 'react-dom';
import { BrowserRouter } from 'react-router-dom';
import App from './App';
import './index.css';

ReactDOM.render(
  <BrowserRouter>
     <App />
   </BrowserRouter>,
  document.getElementById('root')
);

Slider.js：

import React, { Component } from 'react';
import _ from 'lodash';

// components
import AnimatedWrapper from './AnimatedWrapper';
import Separator from './Separator';

// styles
import styles from '../styles/Slider.css';

// images
import Apartment from "../../public/images/apartment.jpg";
import Floor from "../../public/images/floor.jpg";
import Furniture from "../../public/images/furniture.jpg";
import Kitchen1 from "../../public/images/kitchen.jpg";
import Kitchen2 from "../../public/images/kitchen-2.jpg";

class SliderComponent extends Component {
  constructor(props) {
    super(props);

    this.state = {
      currentSlide: 0,
      slides: [Apartment, Floor, Furniture, Kitchen1, Kitchen2]
    };
  }

  componentDidMount() {
    this.zoomAnimation();
    this.slideContentAnimation();

    this.sliderInterval = setInterval(() => {
      if (this.state.currentSlide === 4) {
        if (this.refs.slider) {
          this.setState({ currentSlide: 0 });
        }
      } else {
        if (this.refs.slider) {
          this.setState({ currentSlide: this.state.currentSlide + 1 });
        }
      }
    }, 6000);
  }

  componentWillUpdate() {
    const currentContent = document.getElementById(`content-${this.state.currentSlide}`);
    setTimeout(() => {
      currentContent.classList.remove(`${styles.currentContent}`);
    }, 1500);
  }

  componentDidUpdate() {
    this.zoomAnimation();
    this.slideContentAnimation();
  }

  setSlide(number) {
    this.setState({ currentSlide: number });
  }

  zoomAnimation() {
    setTimeout(() => {
      const currentSlide = document.getElementById(`slide-${this.state.currentSlide}`);
      currentSlide.classList.add(`${styles.slideZoom}`);
    }, 500);
  }

  slideContentAnimation() {
    setTimeout(() => {
      const currentContent = document.getElementById(`content-${this.state.currentSlide}`);
      if (currentContent) {
        currentContent.classList.add(`${styles.currentContent}`);
      }
    }, 1500);
  }

  renderSlides() {
    return this.state.slides.map((slide, index) => {
      const isCurrent = index === this.state.currentSlide;

      const slideStyle = {
        backgroundImage: `url(${this.state.slides[index]})`
      }

      return (
        <div
          id={`slide-${index}`}
          key={`slide-${index}`}
          className={`
            ${styles.slide}
            ${isCurrent ? styles.currentSlide : null}
          `}
          style={slideStyle}
          alt="slide">
            <div
              id={`content-${index}`}
              key={`content-${index}`}
              className={`
                ${styles.content}
            `}>
              <h1>{`WE SPECIALIZE IN KITCHENS ${index}`}</h1>
              <Separator
                containerWidth={720}
                circleWidth={5}
                circleHeight={5}
                backgroundColor="#fff"
                lineWidth={350}
                lineColor="#fff"
              />
              <div
                className={`${styles['hvr-sweep-to-top']} ${styles.btn}`}>
                More Information
              </div>
            </div>
        </div>
      );
    });
  }

  renderNavBar() {
    return (
      <div className={styles.sliderNav}>
        {_.range(5).map((index) => {
          return (
            <div
              key={index}
              onClick={() => this.setSlide(index)}
              className={this.state.currentSlide === index ? styles.current : null}>
            </div>
          )
        })}
      </div>
    )
  }

  render() {
    return (
      <div className={styles.container} ref="slider">
        <div className={styles.slidesContainer}>
          {this.renderSlides()}
        </div>

        {this.renderNavBar()}
      </div>
    );
  }
}

const Slider = AnimatedWrapper(SliderComponent);
export default Slider;

ComingSoon.js：

import React from 'react';
import AnimatedWrapper from './AnimatedWrapper';
import styles from '../styles/ComingSoon.css';

const ComingSoonComponent = function() {
  return (
    <div>
      <div className={styles.mainContent}>
        <div>
          <h1 className={styles.mainTitle}>{`Coming Soon`}</h1>
        </div>
      </div>
    </div>
  );
};

const ComingSoon = AnimatedWrapper(ComingSoonComponent);
export default ComingSoon;

Answer 1

尝试使用react-transition-group会有所帮助。

您可以像本示例一样使用它。 如以下主要代码：

import { BrowserRouter, Route, Switch, Link } from 'react-router-dom'
import { CSSTransition, TransitionGroup } from 'react-transition-group'

const PageFade = (props) => (
  <CSSTransition 
    {...props}
    classNames="fadeTranslate"
    timeout={1000}
    mountOnEnter={true}
    unmountOnExit={true}
  />
)

const Layout = ({ children }) => (
  <section>
    <nav>
      <ul>
        <li><Link to="/">Home</Link></li>
        <li><Link to="/about">About</Link></li>
        <li><Link to="/topics">Non existing</Link></li>
      </ul>
    </nav>
    <hr />
    {children}
  </section>
)

const App = (props) => {
  const locationKey = props.location.pathname

  return (
  <Layout>
    <TransitionGroup>
      <PageFade key={locationKey}>
        <section className="fix-container">
          <Switch location={props.location}>
            <Route exact path="/" component={Home} />
            <Route exact path="/about" component={About} />
            <Route component={NotFound} />
          </Switch>
        </section>
      </PageFade>
    </TransitionGroup>
  </Layout>
  )
}

const BasicExample = () => (
  <BrowserRouter>
    <Route path="/" component={App} />
  </BrowserRouter>
);

render(<BasicExample />, document.getElementById('root'));