一、安装并引入第三方库

npm install react-transition-group --save
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二、对一个元素开发动画

首先利用CSSTransition进行单个元素的动画开发。

//App.js
import { CSSTransition } from 'react-transition-group'
import React, { Component } from 'react';
import './style.css'
class App extends Component {
  constructor(props) {
    super(props);
    this.state = { 
      isShow: true
    }
    this.toToggole = this.toToggole.bind(this)
  }
  render() { 
    return ( 
      <div>
        <CSSTransition
            <!-- in表示是否出现 timeout表示动画延时 -->
            in={this.state.isShow}
            timeout={2000}
            <!-- classNames是钩子名，为后面的class名前缀 -->
            classNames="test"
            <!-- unmountOnExit表示元素隐藏则相应的DOM被移除 -->
            unmountOnExit
            <!-- appear设为true表示进场动画,CSS中有对应类名 -->
            appear={true}
            <!--以下为动画钩子函数, 与CSS中相对应-->
            onEnter={(el) => {}}
            onEntering={(el) => {}}
            onEntered={(el) => {}}
            onExit={(el) => {}}
            onExiting={(el) => {}}
            onExited={(el) => {}}
        >
          <div>hello</div>
        </CSSTransition>
        <div><button onClick={this.toToggole}>点我</button></div>
      </div>  
    );
  }
  toToggole() {
    this.setState({
      isShow: !this.state.isShow
    })
  }
}
 
export default App;
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//进场前的瞬间
.test-enter, .test-appear{
    opacity: 0;
}
//进场过程中
.test-enter-active, .test-appear-active{
    opacity: 1;
    transition: opacity 2000ms;
}
//进场之后
.test-enter-done{
    opacity: 1;
}
//离开前的瞬间
.test-exit{
    opacity: 1;
}
//离开过程中
.test-exit-active{
    opacity: 0;
    transition: opacity 2000ms;
}
//离开后
.test-exit-done{
    opacity: 0;
}
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三、对一组元素进行动画操作

//App.js
//CSS文件和style.css相同
import { CSSTransition, TransitionGroup } from 'react-transition-group'
import React, { Component } from 'react';
import './style.css'
class App extends Component {
  constructor(props) {
    super(props);
    this.state = { 
      list: []
    }
    this.handleAddItem = this.handleAddItem.bind(this)
  }
  render() { 
    return ( 
      <div>
        <TransitionGroup>
        {
          this.state.list.map((item, index) => {
            return (
              <CSSTransition
              timeout={2000}
              classNames="test"
              unmountOnExit
              onEntered={(el) => {el.style.color='blue'}}
              appear={true}
              >
                <div key={index}>{item}</div>
              </CSSTransition>
            )
          })
        }
        </TransitionGroup>
        <div><button onClick={this.handleAddItem}>点我</button></div>
      </div>  
    );
  }
  handleAddItem() {
    this.setState((prevState) => {
      return {
        list: [...prevState.list, 'item']
      }
    })
  }
}
 
export default App;
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今天解锁了react使用动画的新姿势，记录一下，希望对大家有帮助。