我试图找出当所有嵌套转换结束时如何捕获事件。例如,我将一个字符串作为一个孩子,在将其分成单词后,然后将每个单词分成字符,我试图为每个字符设置动画。为此,我用<Transition>
包装每个单词中的所有字符。但是当每个单词中的所有角色都使用过渡动画完成时,我需要捕捉事件。目前onExited
事件在动画开始后立即触发。
在下面的代码中,我需要找到一种方法,当所有角色都用动画完成时,将this.state.showHeadline
设置为true。
链接到Codesandbox
import React from "react";
import { render } from "react-dom";
import { Transition, TransitionGroup } from "react-transition-group";
import styled, { css } from "styled-components";
const Content = styled.div`
display: flex;
`;
const Word = styled.span`
margin-right: 0.5em;
&:last-child {
margin-right: 0;
}
`;
const Char = styled.span`
text-align: center;
min-width: 8px;
color: black;
backface-visibility: visible;
transition: opacity 4.5s, filter 2s;
transition-timing-function: ease-in-out;
-webkit-font-smoothing: antialiased;
webkit-text-stroke: 0.45px;
-webkit-text-stroke: 0.45px rgba(0, 0, 0, 0.1);
transform: perspective(1050px) rotateY(0deg) scale(0.9);
display: inline-block;
opacity: 0;
${props =>
props.state &&
((props.state === "entering" &&
css`
opacity: 0;
`) ||
(props.state === "entered" &&
css`
opacity: 1;
`))}
`;
class TextWrapper extends React.Component {
constructor() {
super();
this.state = {
showTitle: false,
showHeadline: false
};
}
setState(state) {
super.setState(state);
}
componentDidMount() {
setTimeout(
this.setState(prevState => {
return {
showTitle: true
};
}),
1000
);
}
render() {
const content = this.props.children.split(" ").map((word, i) => {
const chars = word.split("").map((char, i, charArray) => {
return (
<Transition
in={this.state.showTitle}
timeout={(i + 0.5) * 400}
key={char + i}
>
{state => <Char state={state}>{char}</Char>}
</Transition>
);
});
return (
<Transition key={i} timeout={0}>
<Word>
<TransitionGroup
appear={true}
component={null}
onEntered={console.log("char")}
>
{chars}
</TransitionGroup>
</Word>
</Transition>
);
});
return (
<React.Fragment>
<Content>
<TransitionGroup appear={true} component={null} onExited={null}>
{content}
</TransitionGroup>
</Content>
{this.state.showHeadline && <Content>Hello</Content>}
</React.Fragment>
);
}
}
const App = () => <TextWrapper>Example Text</TextWrapper>;
const root = document.getElementById("app");
if (root) {
render(<App />, root);
}
你需要设置一个计数器和一个监听器。当一个单词的动画结束时,计数+1并监听计数是否等于单词长度。如果相等,请运行this.state.showHeadline
。