React 样式组件淡出 in/fade

Question

我正在尝试构建一个 React 组件来处理淡入和淡出。在下面的代码中，如果我将 out 作为道具传递给组件，它会在动画出来之前显示为隐藏。我试图让它默认淡入，然后在我传入 out 道具时淡出。有人看到这个问题的解决方案吗？

import React from 'react';
import styled, { keyframes } from 'styled-components';

const fadeIn = keyframes`
  from {
    transform: scale(.25);
    opacity: 0;
  }

  to {
    transform: scale(1);
    opacity: 1;
  }
`;

const fadeOut = keyframes`
  from {
    transform: scale(1);
    opacity: 0;
  }

  to {
    transform: scale(.25);
    opacity: 1;
  }
`;

const Fade = styled.div`
  ${props => props.out ?
    `display: none;`
   : `display: inline-block;`
   }
  animation: ${props => props.out ? fadeOut : fadeIn} 1s linear infinite;
`;

function App() {
  return (
    <div>
      <Fade>&lt;test&gt;</Fade>
    </div>
  );
}

export default App;

WebpackBin running example

Answer 1

您的代码存在的问题是当 props.out 为真时，您将显示属性设置为 none。这就是您看不到任何动画的原因，因为在动画开始之前您已经隐藏了组件！

制作淡出动画的方法是改用可见性属性并在与动画所用时间相同的时间内进行过渡。（参见 this old SO answer）

像这样应该可以解决您的问题：

const Fade = styled.default.div`
  display: inline-block;
  visibility: ${props => props.out ? 'hidden' : 'visible'};
  animation: ${props => props.out ? fadeOut : fadeIn} 1s linear;
  transition: visibility 1s linear;
`;

const fadeIn = styled.keyframes`
  from {
    transform: scale(.25);
    opacity: 0;
  }

  to {
    transform: scale(1);
    opacity: 1;
  }
`;

const fadeOut = styled.keyframes`
  from {
    transform: scale(1);
    opacity: 1;
  }

  to {
    transform: scale(.25);
    opacity: 0;
  }
`;

const Fade = styled.default.div`
  display: inline-block;
  visibility: ${props => props.out ? 'hidden' : 'visible'};
  animation: ${props => props.out ? fadeOut : fadeIn} 1s linear;
  transition: visibility 1s linear;
`;

class App extends React.Component {
  constructor() {
    super()
    this.state = {
      visible: true,
    }
  }

  componentDidMount() {
    setTimeout(() => {
      this.setState({
        visible: false,
      })
    }, 1000)
  }

  render() {
    return (
      <div>
        <Fade out={!this.state.visible}>&lt;test&gt;</Fade>
      </div>
    );
  }
}

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

<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react-dom.min.js"></script>
<script src="https://unpkg.com/styled-components/dist/styled-components.min.js"></script>

<div id="root" />

注意：您的淡出动画的不透明度也从 0 变为 1，而不是相反。我也在代码段中修复了它。

React 样式组件淡出 in/fade

React styled-components fade in/fade out

reactjs

styled-components