如何在MUI中设置ListItem的选中和悬停颜色？

2022-02-22 00:00:00 reactjs css material-ui

无法使"选定"或"悬停颜色"适用于ListItem。对于选定的已尝试设置其类，如下所示：

<ListItem selected button key="home" classes={{ selected: classes.listItemSelected }}>
  <ListItemText primary="Hi"/>
</ListItem>

然后设置样式，如下所示：

const useStyles = makeStyles((theme) => ({
  listItemSelected:{
    backgroundColor: "#ff0000",
  },
}));

但不做任何事情，ListItem组件接口here中描述了‘Selected’。

如何设置ListItem的选定和悬停的颜色？

解决方案

下面是default ListItem styles中处理背景颜色的部分：

export const styles = (theme) => ({
  /* Styles applied to the (normally root) `component` element. May be wrapped by a `container`. */
  root: {
    '&$focusVisible': {
      backgroundColor: theme.palette.action.selected,
    },
    '&$selected, &$selected:hover': {
      backgroundColor: theme.palette.action.selected,
    },
    '&$disabled': {
      opacity: 0.5,
    },
  },
  /* Pseudo-class applied to the `component`'s `focusVisibleClassName` prop if `button={true}`. */
  focusVisible: {},
  /* Styles applied to the inner `component` element if `button={true}`. */
  button: {
    transition: theme.transitions.create('background-color', {
      duration: theme.transitions.duration.shortest,
    }),
    '&:hover': {
      textDecoration: 'none',
      backgroundColor: theme.palette.action.hover,
      // Reset on touch devices, it doesn't add specificity
      '@media (hover: none)': {
        backgroundColor: 'transparent',
      },
    },
  },
  /* Pseudo-class applied to the root element if `selected={true}`. */
  selected: {},
});

需要注意的重要一点是，选定的样式是通过两个类(root和selected)的组合来完成的，因此，如果您尝试使用单个类覆盖它，specificity将不会有足够的specificity。

下面的示例显示了覆盖选定和悬停状态的一种方法：

import React from "react";
import { makeStyles, withStyles } from "@material-ui/core/styles";
import List from "@material-ui/core/List";
import MuiListItem from "@material-ui/core/ListItem";
import ListItemIcon from "@material-ui/core/ListItemIcon";
import ListItemText from "@material-ui/core/ListItemText";
import Divider from "@material-ui/core/Divider";
import InboxIcon from "@material-ui/icons/Inbox";
import DraftsIcon from "@material-ui/icons/Drafts";

const useStyles = makeStyles((theme) => ({
  root: {
    width: "100%",
    maxWidth: 360,
    backgroundColor: theme.palette.background.paper
  }
}));

const ListItem = withStyles({
  root: {
    "&$selected": {
      backgroundColor: "red",
      color: "white",
      "& .MuiListItemIcon-root": {
        color: "white"
      }
    },
    "&$selected:hover": {
      backgroundColor: "purple",
      color: "white",
      "& .MuiListItemIcon-root": {
        color: "white"
      }
    },
    "&:hover": {
      backgroundColor: "blue",
      color: "white",
      "& .MuiListItemIcon-root": {
        color: "white"
      }
    }
  },
  selected: {}
})(MuiListItem);

export default function SelectedListItem() {
  const classes = useStyles();
  const [selectedIndex, setSelectedIndex] = React.useState(1);

  const handleListItemClick = (event, index) => {
    setSelectedIndex(index);
  };

  return (
    <div className={classes.root}>
      <List component="nav" aria-label="main mailbox folders">
        <ListItem
          button
          selected={selectedIndex === 0}
          onClick={(event) => handleListItemClick(event, 0)}
        >
          <ListItemIcon>
            <InboxIcon />
          </ListItemIcon>
          <ListItemText primary="Inbox" />
        </ListItem>
        <ListItem
          button
          selected={selectedIndex === 1}
          onClick={(event) => handleListItemClick(event, 1)}
        >
          <ListItemIcon>
            <DraftsIcon />
          </ListItemIcon>
          <ListItemText primary="Drafts" />
        </ListItem>
      </List>
      <Divider />
      <List component="nav" aria-label="secondary mailbox folder">
        <ListItem
          button
          selected={selectedIndex === 2}
          onClick={(event) => handleListItemClick(event, 2)}
        >
          <ListItemText primary="Trash" />
        </ListItem>
        <ListItem
          button
          selected={selectedIndex === 3}
          onClick={(event) => handleListItemClick(event, 3)}
        >
          <ListItemText primary="Spam" />
        </ListItem>
      </List>
    </div>
  );
}