Material-ui模式forwardRef警告

Question

这是让用户登录的表单，我在这里使用了forwardRef，在SignInModal中我包装了这个组件，但它总是给我警告

import React, { useState, useEffect } from "react";
import PropTypes from "prop-types";
import Avatar from "@material-ui/core/Avatar";
import Button from "@material-ui/core/Button";
import CssBaseline from "@material-ui/core/CssBaseline";
import FormControl from "@material-ui/core/FormControl";
import FormControlLabel from "@material-ui/core/FormControlLabel";
import Checkbox from "@material-ui/core/Checkbox";
import Input from "@material-ui/core/Input";
import InputLabel from "@material-ui/core/InputLabel";
import LockOutlinedIcon from "@material-ui/icons/LockOutlined";
import Paper from "@material-ui/core/Paper";
import Typography from "@material-ui/core/Typography";
import withStyles from "@material-ui/core/styles/withStyles";
import { connect } from "react-redux";
import { login } from "../actions/auth";
import Grid from "@material-ui/core/Grid";
import Link from "@material-ui/core/Link";
import Alert from "./Alert";
import { Link as RouterLink } from "react-router-dom";

const styles = theme => ({
  main: {
    width: "auto",
    display: "block", // Fix IE 11 issue.
    marginLeft: theme.spacing(3),
    marginRight: theme.spacing(3),
    [theme.breakpoints.up(400 + theme.spacing(3 * 2))]: {
      width: 400,
      marginLeft: "auto",
      marginRight: "auto"
    }
  },
  paper: {
    marginTop: theme.spacing(8),
    display: "flex",
    flexDirection: "column",
    alignItems: "center",
    padding: `${theme.spacing(2)}px ${theme.spacing(3)}px ${theme.spacing(3)}px`
  },
  avatar: {
    margin: theme.spacing(),
    backgroundColor: "black"
  },
  form: {
    width: "100%", // Fix IE 11 issue.
    marginTop: theme.spacing()
  },
  submit: {
    marginTop: theme.spacing(3)
  }
});

// const SignIn = props => {
const SignIn = React.forwardRef((props, ref) => {
  const { classes, isAuthenticated, login, modalControl } = props;
  const [formData, setFormData] = useState({
    email: "",
    password: ""
  });
  const { email, password } = formData;
  const onChange = e =>
    setFormData({ ...formData, [e.target.name]: e.target.value });
  const onSubmit = async e => {
    e.preventDefault();
    login(email, password);
  };
  if (isAuthenticated) {
    modalControl();
  }

  //  else if (password != password1) {
  //   setAlert("password do not match", "danger");
  // }

  return (
    <main ref={ref} className={classes.main}>
      <CssBaseline />
      <Paper className={classes.paper}>
        <Avatar className={classes.avatar}>
          <LockOutlinedIcon />
        </Avatar>
        <Typography component="h1" variant="h5">
          Sign in
        </Typography>
        <Alert />
        <form className={classes.form} onSubmit={e => onSubmit(e)}>
          <FormControl margin="normal" fullWidth>
            <InputLabel htmlFor="email">Email Address</InputLabel>
            <Input
              id="email"
              name="email"
              autoComplete="email"
              value={email}
              onChange={e => onChange(e)}
              autoFocus
            />
          </FormControl>
          <FormControl margin="normal" fullWidth>
            <InputLabel htmlFor="password">Password</InputLabel>
            <Input
              name="password"
              type="password"
              id="password"
              value={password}
              onChange={e => onChange(e)}
              autoComplete="current-password"
            />
          </FormControl>
          <FormControlLabel
            control={<Checkbox value="remember" color="primary" />}
            label="Remember me"
          />
          <Button
            type="submit"
            fullWidth
            variant="contained"
            color="default"
            className={classes.submit}
          >
            Sign in
          </Button>
          <Grid container>
            <Grid item xs>
              <Link
                variant="body2"
                component={RouterLink}
                to="/PasswordReset"
                underline="none"
              >
                Forgot password?
              </Link>
            </Grid>
            <Grid item>
              <Link href="#" variant="body2">
                {"Don't have an account? Sign Up"}
              </Link>
            </Grid>
          </Grid>
        </form>
      </Paper>
    </main>
  );
});

SignIn.propTypes = {
  classes: PropTypes.object.isRequired,
  login: PropTypes.func.isRequired,
  isAuthenticated: PropTypes.bool,
  modalControl: PropTypes.func.isRequired
};
const mapStateToProps = state => ({
  isAuthenticated: state.auth.isAuthenticated
});

export default connect(mapStateToProps, { login })(withStyles(styles)(SignIn));






import React, { useState, useRef, useEffect } from "react";
import PropTypes from "prop-types";
import { withStyles } from "@material-ui/core/styles";
import Typography from "@material-ui/core/Typography";
import Modal from "@material-ui/core/Modal";
import Button from "@material-ui/core/Button";
import SignIn from "./SignIn";

function getModalStyle() {
  const top = 25;
  const left = 25;

  return {
    top: `${top}%`,
    left: `${left}%`,
    transform: `translate(-${top}%, -${left}%)`
  };
}

const styles = theme => ({
  button: {
    margin: theme.spacing(1)
  }
});

const SigninModal = props => {
  const [open, setOpen] = useState(false);

  const handleOpen = () => {
    setOpen(true);
  };

  const handleClose = () => {
    setOpen(false);
  };

  const { classes, SigninModalRef } = props;

  return (
    <div>
      <Button
        className={classes.button}
        variant="contained"
        onClick={handleOpen}
      >
        Sign In
      </Button>
      <Modal
        aria-labelledby="simple-modal-title"
        aria-describedby="simple-modal-description"
        open={open}
        onClose={handleClose}
      >
        <SignIn modalControl={handleClose} />
      </Modal>
    </div>
  );
};

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



export default withStyles(styles)(SigninModal);

我使用Signinmodal包装了Signin表单，不确定我是否正确地使用了forwardref，它仍然给我警告“函数组件不能被给予引用”。访问此引用的尝试将失败。您的意思是使用React.forwardRef()吗？“

Answer 1

使用ref为我解决了问题。在你的情况下

<SignIn ref={ref} modalControl={handleClose} />

const SigninModal = React.forwardRef( (ref, props) => {
return (
    <div ref={ref}>
   ... rest of the code
})