Question

我正在处理我的 React 表单，我有以下代码：

import { useState } from "react";

const SignupComponent = () => {
  const [values, setValues] = useState({
    name: "",
    email: "",
    password: "",
    error: "",
    loading: false,
    message: "",
    showForm: true,
  });

  const { name, email, password, error, loading, message, showForm } = values;

  const handleSubmit = (e) => {
    e.preventDefault();
    console.table({ name, email, password, error, loading, message, showForm });
  };

  const handleChange = (name) => (e) => {
    setValues({ ...values, error: false, [name]: e.target.value });
  };

  const signupForm = () => {
    return (
      <form onSubmit={handleSubmit}>
        <div className="form-group mt-3">
          <input
            onChange={handleChange("name")}
            type="text"
            className="form-control"
            placeholder="Type your name"
            value={name}
          />
        </div>

        <div className="form-group mt-3">
          <input
            onChange={handleChange("email")}
            type="email"
            className="form-control"
            placeholder="Type your email"
            value={email}
          />
        </div>

        <div className="form-group mt-3">
          <input
            onChange={handleChange("password")}
            type="password"
            className="form-control"
            placeholder="Type your password"
            value={password}
          />
        </div>

        <div className="form-group mt-3">
          <div className="btn btn-primary">Signup</div>
        </div>
      </form>
    );
  };

  return <>{signupForm()}</>;
};

export default SignupComponent;

当我访问我的表单并填写字段时，它实际上应该控制台记录姓名、电子邮件等的值。但是，它返回以下错误：

Warning: Function components cannot be given refs. Attempts to access this ref will fail. Did you mean to use React.forwardRef()?

Check the render method of `Link`.
    at NavbarBrand (http://localhost:3000/_next/static/chunks/pages/signup.js?ts=1620610614705:48922:25)
    at Link (http://localhost:3000/_next/static/chunks/pages/signup.js?ts=1620610614705:1587:19)
    at nav
    at Navbar (http://localhost:3000/_next/static/chunks/pages/signup.js?ts=1620610614705:48863:22)
    at div
    at Container (http://localhost:3000/_next/static/chunks/main.js?ts=1620610614705:8388:5)
    at AppContainer (http://localhost:3000/_next/static/chunks/main.js?ts=1620610614705:8876:24)
    at Root (http://localhost:3000/_next/static/chunks/main.js?ts=1620610614705:9012:25)
printWarning @ react-dom.development.js:67
error @ react-dom.development.js:43
unbatchedUpdates @ react-dom.development.js:22431
legacyRenderSubtreeIntoContainer @ react-dom.development.js:26020
hydrate @ react-dom.development.js:26086
renderReactElement @ index.tsx:524
doRender @ index.tsx:793
_callee2$ @ index.tsx:425
tryCatch @ runtime.js:63
invoke @ runtime.js:293
(anonymous) @ main.js?ts=1620610614705:1
react-dom.development.js:67 Warning: Expected server HTML to contain a matching <a> in <a>.

知道是什么原因导致表单没有 console.log 吗？我检查了每个表单字段。

Answer 1

您可能已将 ref 分配给 SignupComponent 或其他一些功能组件。

<SignupComponent ref={someRef}>

函数组件不能被赋予引用，因为它们没有实例。删除 ref 将修复警告，或者如果您想将 ref 分配给组件中的某些输入字段，则可以使用 forwardRef。

有关转发引用的更多信息：https://reactjs.org/docs/forwarding-refs.html

尝试访问此引用将失败。你的意思是使用 React.forwardRef()

1 个答案: