Material ui popover 如何锚定到另一个元素（与事件目标不同）

Question

通常，当我们使用 popover 时，我们将鼠标事件期间的锚点设置为event.currentTarget。

然而，这在某些情况下是不可能的，而在其他情况下是不受欢迎的。- 如何直接设置弹出框锚元素？

import React from "react";
import Popover from "@material-ui/core/Popover";
import Typography from "@material-ui/core/Typography";
import Button from "@material-ui/core/Button";

export default function SimplePopover() {
  const [anchorEl, setAnchorEl] = React.useState(null);

  function handleClick(event) {
    //setAnchorEl(event.currentTarget);
    setAnchorEl(); //How to refer to the div?
  }

  function handleClose() {
    setAnchorEl(null);
  }

  const open = Boolean(anchorEl);
  const id = open ? "simple-popover" : undefined;

  return (
    <div>
      <Typography>Anchor point of popover here</Typography>
      <Button aria-describedby={id} variant="contained" onClick={handleClick}>
        Open Popover
      </Button>
      <Popover
        id={id}
        open={open}
        anchorEl={anchorEl}
        onClose={handleClose}
        anchorOrigin={{
          vertical: "bottom",
          horizontal: "center"
        }}
        transformOrigin={{
          vertical: "top",
          horizontal: "center"
        }}
      >
        <Typography>The content of the Popover.</Typography>
      </Popover>
    </div>
  );
}

演示

Answer 1

您可以使用 ref 来获取要用作锚点的任何元素：

import React from "react";
import Popover from "@material-ui/core/Popover";
import Typography from "@material-ui/core/Typography";
import Button from "@material-ui/core/Button";

export default function SimplePopover() {
  const [anchorEl, setAnchorEl] = React.useState(null);
  const divRef = React.useRef();
  function handleClick() {
    setAnchorEl(divRef.current);
  }

  function handleClose() {
    setAnchorEl(null);
  }

  const open = Boolean(anchorEl);
  const id = open ? "simple-popover" : undefined;

  return (
    <div ref={divRef}>
      <Typography>Anchor point of popover here</Typography>
      <Button aria-describedby={id} variant="contained" onClick={handleClick}>
        Open Popover
      </Button>
      <Popover
        id={id}
        open={open}
        anchorEl={anchorEl}
        onClose={handleClose}
        anchorOrigin={{
          vertical: "bottom",
          horizontal: "center"
        }}
        transformOrigin={{
          vertical: "top",
          horizontal: "center"
        }}
      >
        <Typography>The content of the Popover.</Typography>
      </Popover>
    </div>
  );
}