30秒学会 React 片段 – Tooltip

Renders a tooltip component.

• Use the React.useState() hook to create the show variable and initialize it to false.
• Return a <div> element that contains the <div> that will be the tooltip and the children passed to the component.
• Handle the onMouseEnter and onMouseLeave methods, by altering the value of the show variable.

代码实现

.tooltip {
  position: relative;
  background: rgba(0, 0, 0, 0.7);
  color: white;
  visibility: hidden;
  padding: 5px;
  border-radius: 5px;
}
.tooltip-arrow {
  position: absolute;
  top: 100%;
  left: 50%;
  border-width: 5px;
  border-style: solid;
  border-color: rgba(0, 0, 0, 0.7) transparent transparent;
}

使用样例

function Tooltip({ children, text, ...rest }) {
  const [show, setShow] = React.useState(false);

  return (
    <div>
      <div className="tooltip" style={show ? { visibility: 'visible' } : {}}>
        {text}
        <span className="tooltip-arrow" />
      </div>
      <div {...rest} onMouseEnter={() => setShow(true)} onMouseLeave={() => setShow(false)}>
        {children}
      </div>
    </div>
  );
}

ReactDOM.render(
  <Tooltip text="Simple tooltip">
    <button>Hover me!</button>
  </Tooltip>,
  document.getElementById('root')
);