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如何在React中使选择菜单相对于控制器按钮的位置?

reactjs css

Let Me Tink About It · 技术社区 · 7 年前

我想实现一个 <Select /> 具有两个特征的组件。

我想隐藏窗体控件。如图1所示。我现在通过使用 display: 'none' . CodeSandbox Demo
我想让选择菜单直接出现在打开菜单的按钮下面。如图2所示。目前,它似乎完全位于窗口的左上角。 CodeSandbox Demo

如何实现这两个功能?(答案的代码沙盒演示将非常有用。)

图1。

https://codesandbox.io/s/j7xr2wmw7v

import React from "react";
import PropTypes from "prop-types";
import { withStyles } from "@material-ui/core/styles";
import InputLabel from "@material-ui/core/InputLabel";
import MenuItem from "@material-ui/core/MenuItem";
import FormControl from "@material-ui/core/FormControl";
import Select from "@material-ui/core/Select";
import Button from "@material-ui/core/Button";

const styles = theme => ({
  button: {
    display: "block",
    marginTop: theme.spacing.unit * 30
  },
  formControl: {
    margin: theme.spacing.unit,
    minWidth: 120,
    display: "none"
  }
});

class ControlledOpenSelect extends React.Component {
  state = {
    age: "",
    open: false
  };

  handleChange = event => {
    this.setState({ [event.target.name]: event.target.value });
  };

  handleClose = () => {
    this.setState({ open: false });
  };

  handleOpen = () => {
    this.setState({ open: true });
  };

  render() {
    const { classes } = this.props;

    return (
      <form autoComplete="off">
        <Button className={classes.button} onClick={this.handleOpen}>
          Open the select
        </Button>
        <FormControl hidden className={classes.formControl}>
          <InputLabel htmlFor="demo-controlled-open-select">Age</InputLabel>
          <Select
            open={this.state.open}
            onClose={this.handleClose}
            onOpen={this.handleOpen}
            value={this.state.age}
            onChange={this.handleChange}
            inputProps={{
              name: "age",
              id: "demo-controlled-open-select"
            }}
          >
            <MenuItem value="">
              <em>None</em>
            </MenuItem>
            <MenuItem value={10}>Ten</MenuItem>
            <MenuItem value={20}>Twenty</MenuItem>
            <MenuItem value={30}>Thirty</MenuItem>
          </Select>
        </FormControl>
      </form>
    );
  }
}

ControlledOpenSelect.propTypes = {
  classes: PropTypes.object.isRequired
};

export default withStyles(styles)(ControlledOpenSelect);

图2。 下拉选择菜单显示在按钮的正下方

https://codesandbox.io/s/l4k8p7zxjq

import React from 'react';
import PropTypes from 'prop-types';
import { withStyles } from '@material-ui/core/styles';
import InputLabel from '@material-ui/core/InputLabel';
import MenuItem from '@material-ui/core/MenuItem';
import FormControl from '@material-ui/core/FormControl';
import Select from '@material-ui/core/Select';
import Button from '@material-ui/core/Button';

const styles = theme => ({
  button: {
    display: 'block',
    marginTop: theme.spacing.unit * 2,
  },
  formControl: {
    margin: theme.spacing.unit,
    minWidth: 120,
  },
});

class ControlledOpenSelect extends React.Component {
  state = {
    age: '',
    open: false,
  };

  handleChange = event => {
    this.setState({ [event.target.name]: event.target.value });
  };

  handleClose = () => {
    this.setState({ open: false });
  };

  handleOpen = () => {
    this.setState({ open: true });
  };

  render() {
    const { classes } = this.props;

    return (
      <form autoComplete="off">
        <Button className={classes.button} onClick={this.handleOpen}>
          Open the select
        </Button>
        <FormControl className={classes.formControl}>
          <InputLabel htmlFor="demo-controlled-open-select">Age</InputLabel>
          <Select
            open={this.state.open}
            onClose={this.handleClose}
            onOpen={this.handleOpen}
            value={this.state.age}
            onChange={this.handleChange}
            inputProps={{
              name: 'age',
              id: 'demo-controlled-open-select',
            }}
          >
            <MenuItem value="">
              <em>None</em>
            </MenuItem>
            <MenuItem value={10}>Ten</MenuItem>
            <MenuItem value={20}>Twenty</MenuItem>
            <MenuItem value={30}>Thirty</MenuItem>
          </Select>
        </FormControl>
      </form>
    );
  }
}

ControlledOpenSelect.propTypes = {
  classes: PropTypes.object.isRequired,
};

export default withStyles(styles)(ControlledOpenSelect);

1 回复 | 直到 7 年前

derelict 7 年前

而不是

display: "none"

尝试

visibility: "hidden",
width:'0',
height:'0'