如何使用React-Hook-Form设置ref焦点

Question

如何使用React-Hook-Form在输入中实现set focus，这就是他们的常见问题“如何共享引用用法”的代码，这里是https://www.react-hook-form.com/faqs/#Howtosharerefusage

import React, { useRef } from "react";
import { useForm } from "react-hook-form";

export default function App() {
  const { register, handleSubmit } = useForm();
  const firstNameRef = useRef();
  const onSubmit = data => console.log(data);

  return (
    <form onSubmit={handleSubmit(onSubmit)}>
      <input name="firstName" ref={(e) => {
        register(e)
        firstNameRef.current = e // you can still assign to ref
      }} />
      <input name="lastName" ref={(e) => {
        // register's first argument is ref, and second is validation rules
        register(e, { required: true })
      }} />

      <button>Submit</button>
    </form>
  );
}

我尝试在useEffect中设置ref的焦点，但它不起作用：

useEffect(()=>{
   firstNameRef.current.focus();
},[])

在输入内部也是如此：

<input name="firstName" ref={(e) => {
    register(e)
    firstNameRef.current = e;
    e.focus();
}} />

Answer 1

您可以使用useForm钩子返回的setFocus助手设置焦点(不需要使用自定义引用)：

 const allMethods = useForm();
 const { setFocus } = allMethods;

 ...

 setFocus('inputName');

https://react-hook-form.com/api/useform/setFocus

Answer 2

你在使用Typescript吗？

如果是，请替换...

const firstNameRef = useRef();

和..。

const firstNameRef = useRef<HTMLInputElement | null>(null);

Answer 3

useEffect(() => {
if (firstNameRef.current) {
      register(firstNameRef.current)
      firstNameRef.current.focus()
    }
}, []);

<input name="firstName" ref={firstNameRef} />

获取自：https://github.com/react-hook-form/react-hook-form/issues/230