【前端知识】React 基础巩固(二十九)——过渡动画 react-transition-group

React 基础巩固(二十九)——过渡动画 react-transition-group

过渡动画 react-transition-group

react-transition-group 包含：

1. Transition（该组件是一个和平台无关的组件，不一定结合 CSS）
2. CSSTransition（通常使用此组件实现过渡动画效果）
3. SwitchTransition（两个组件显示/隐藏切换时使用）
4. TransitionGroup（将多个动画包裹其中，一般用于列表中元素的动画）

CSSTransition

• CSSTransition 基于 Transition 组件构建

• CSSTransition 执行过程中，有三个状态：appear、enter、exit

• 它们有三种状态，需要定义对应的 CSS 样式

  • 开始状态：-apper,-enter,exit
  • 执行动画：-appear-active,-enter-active,-exit-active
  • 执行结束：-appear-done,-enter-done,-exit-done

• 常见属性

  • in: 触发进入或者退出状态
  • className: 动画 class 的名称
  • timeout: 过渡动画的时间
  • appear: 是否在初次进入添加动画（需要和 in 同时为 true）
  • unmountOnExit: 退出后卸载组件

• 钩子函数

  • onEnter: 在进入动画之前被触发
  • onEntering: 在应用进入动画时被触发
  • onEntered: 在应用进入动画结束后被触发

• 基本使用

import React, { PureComponent } from "react";
import { CSSTransition } from "react-transition-group";
import "./style.css";

export class App extends PureComponent {
  constructor() {
    super();

    this.state = {
      isShowTitle: true,
    };
  }
  render() {
    const { isShowTitle } = this.state;

    return (
      <div>
        <button
          onClick={(e) =>
            this.setState({
              isShowTitle: !isShowTitle,
            })
          }
        >
          change
        </button>
        <CSSTransition
          in={isShowTitle}
          classNames="csst"
          timeout={2000}
          unmountOnExit={true}
          appear
          onEnter={(e) => console.log("on enter")}
          onEntering={(e) => console.log("on entering")}
          onEntered={(e) => console.log("on entered")}
          onExit={(e) => console.log("on exit")}
          onExiting={(e) => console.log("on exiting")}
          onExited={(e) => console.log("on exited")}
        >
          <h2>App</h2>
        </CSSTransition>
      </div>
    );
  }
}

export default App;

.csst-apear {
  transform: translateX(-150px);
}

.csst-apear-active {
  transform: translateX(0);
  transition: transform 2s ease;
}

.csst-apear .csst-enter {
  opacity: 0;
}

.csst-apear-active .csst-enter-active {
  opacity: 1;
  transition: opacity 2s ease;
}

.csst-exit {
  opacity: 1;
}

.csst-exit-active {
  opacity: 0;
  transition: opacity 2s ease;
}

SwitchTransition

• • 常见属性
  • mode
    • in-out: 新组件先进入，旧组件再移除
    • out-in: 旧组件先移除，新组件再进入

• 基本使用

import React, { PureComponent } from "react";
import { SwitchTransition, CSSTransition } from "react-transition-group";
import "./style.css";

export class App extends PureComponent {
  constructor() {
    super();

    this.state = {
      isLogin: true,
    };
  }

  render() {
    const { isLogin } = this.state;
    return (
      <div>
        <SwitchTransition mode="out-in">
          <CSSTransition
            key={isLogin ? "exit" : "login"}
            classNames="login"
            timeout={1000}
          >
            <button
              onClick={(e) =>
                this.setState({
                  isLogin: !isLogin,
                })
              }
            >
              {isLogin ? "退出" : "登录"}
            </button>
          </CSSTransition>
        </SwitchTransition>
      </div>
    );
  }
}

export default App;

.login-enter {
  transform: translateX(100px);
  opacity: 0;
}

.login-enter-active {
  transform: translateX(0);
  opacity: 1;
  transition: all 1s ease;
}

.login-exit {
  transform: translateX(0);
  opacity: 1;
}

.login-exit-active {
  transform: translateX(-100px);
  opacity: 0;
  transition: all 1s ease;
}

TransitionGroup

• 基本使用

import React, { PureComponent } from "react";
import { CSSTransition, TransitionGroup } from "react-transition-group";
import "./style.css";

export class App extends PureComponent {
  constructor() {
    super();
    this.state = {
      books: [
        { id: 1, name: "book1", price: 123, count: 99 },
        { id: 2, name: "book2", price: 223, count: 99 },
        { id: 3, name: "book3", price: 323, count: 99 },
        { id: 4, name: "book4", price: 423, count: 99 },
        { id: 5, name: "book5", price: 523, count: 99 },
      ],
    };
  }

  addNewBook() {
    const books = [...this.state.books];
    books.push({
      id: new Date().getTime(),
      name: "book6",
      price: 111,
      count: 99,
    });
    this.setState({
      books,
    });
  }

  delBook(index) {
    const books = [...this.state.books];
    books.splice(index, 1);
    this.setState({
      books,
    });
  }

  render() {
    const { books } = this.state;
    return (
      <div>
        <h2>书籍列表</h2>
        <TransitionGroup component="ul">
          {books.map((item, index) => {
            return (
              <CSSTransition key={item.id} classNames="book" timeout={1000}>
                <li>
                  <span>
                    {item.name} - {item.price}
                  </span>
                  <button onClick={(e) => this.delBook(index)}>删除书籍</button>
                </li>
              </CSSTransition>
            );
          })}
        </TransitionGroup>
        <button onClick={(e) => this.addNewBook()}>添加新书籍</button>
      </div>
    );
  }
}

export default App;