Question

所以我在使用onMouseHover时尝试显示其他文本，但我似乎无法理解它，就像我试图找出一种方法而不必使用CSS或JQuery。如何根据函数调用使onMouseHover显示文本？

    function URL() {
        return (
            <a href={url} onMouseOver={mouseOver()}>{mouseOver()}</a>
        );
    }
    function mouseOver() {
        return (
            <p>Hovering</p>
        );
    }

Answer 1

class HoverableComponent extends React.Component {
   constructor() {
     super();
     this.state = { text : '' }
   }
   //set the text
   onMouseover (e) {
     this.setState({text : 'some text'})
   }
   //clear the text
   onMouseout (e) {
     this.setState({text : ''})
   }
   render () {
      const {text} = this.state;
      return (
        <div 
          onMouseEnter={this.onMouseover.bind(this)}
          onMouseLeave={this.onMouseout.bind(this)}>{text}</div>
      )
   }
}

Answer 2

您可以使用onMouseEnter和onMouseLeave的组合来更改状态（您需要在构造函数中初始化）。例如：

    function URL() {
      return (
        <a href={url} onMouseEnter={showText()} onMouseLeave={hideText()}>{this.state.text}</a>
      );
    }
    function showText() {
      this.setState({text : "Hovering"}) 
    } 
    function hideText() {
      this.setState({text : ""}) 
    }

Answer 3

这是一个 useHover 反应钩子。

如果您需要跟踪多个 dom 元素的悬停状态，它应该使它更清晰。

import { useState } from 'react'

function useHover() {
  const [hovering, setHovering] = useState(false)
  const onHoverProps = {
    onMouseEnter: () => setHovering(true),
    onMouseLeave: () => setHovering(false),
  }
  return [hovering, onHoverProps]
}

function myComponent() {
  const [buttonAIsHovering, buttonAHoverProps] = useHover()
  const [buttonBIsHovering, buttonBHoverProps] = useHover()

  return (
    <div>
      <button  {...buttonAHoverProps}>
        {buttonAIsHovering ? "button A hovering" : "try hovering here"}
      </button>
      <button  {...buttonBHoverProps}>
        {buttonBIsHovering ? "button B hovering" : "try hovering here"}
      </button>
    </div>
  )
}

React / JS - onMouseOver更改文本

3 个答案: