Question

js和钩子，我一直在收到这些警告，但我不明白为什么，我确实阅读了React文档，但仍然不明白

./ src / CustomerList.js 第32：6行：React Hook useEffect缺少依赖项：'loadData'。包括它或删除依赖数组react-hooks / exhaustive-deps

./ src / CustomerForm.js 第44：9行：React Hook useEffect缺少依赖项：'setValue'。包括它或删除依赖数组react-hooks / exhaustive-deps

如果问题不在useEffect本身中，我将仅粘贴孔代码一侧。

const CustomerForm = ({customer, saveSuccess}) => {
    const { register, handleSubmit, errors, setValue, reset } = useForm();

    const onSubmit = (data, e) => {
      e.preventDefault();
      if (customer) {
        data.id = customer.id;
        axios.put(BASE_URL, {
            id : data.id,
            firstName : data.firstName,
            lastName : data.lastName,
            phoneNumber:data.phoneNumber,
            email : data.email
        }).then(response => {
            alert("Se actualizó exitosamente.")
        })
    } else {
        axios.post(BASE_URL,  {
            firstName : data.firstName,
            lastName : data.lastName,
            phoneNumber:data.phoneNumber,
            email : data.email
        }).then(response => {
                alert("Se guardó exitosamente.")
            })
    }
    saveSuccess();
    };


    useEffect(() => {
        if (customer) {
            setValue("firstName", customer.firstName);
            setValue("lastName", customer.lastName);
            setValue("phoneNumber", customer.phoneNumber);
            setValue("email", customer.email);
        }
     },[customer]);


    return (
        <form onSubmit={handleSubmit(onSubmit)} noValidate>
          <Input
            name="firstName"
            inputRef={register({ required: true})}
            placeholder="First Name"
            error={!!errors.firstName}
            fullWidth
          />
           <p style={{color: "red"}}>{errors.firstName && "First Name is required"}</p>
           <Input
            name="lastName"
       //     setValue = {customerForm.lastName}
            inputRef={register({ required: true})}
            placeholder="Last Name"
            error={!!errors.lastName}
            fullWidth
          />
           <p style={{color: "red"}}>{errors.lastName && "Last Name is required"}</p>
           <Input
            name="phoneNumber"
         //   setValue = {customerForm.phoneNumber}
            inputRef={register({ required: true})}
            placeholder="Phone Number"
            error={!!errors.phoneNumber}
            fullWidth
          />
           <p style={{color: "red"}}>{errors.phoneNumber && "Phone Number is required"}</p>
           <Input
            name="email"
       //     setValue = {customerForm.email}
            inputRef={register({ required: true})}
            placeholder="Email"
            error={!!errors.email}
            fullWidth
          />
           <p style={{color: "red"}}>{errors.email && "Email is required"}</p>

        <Button
                variant="contained"
                color="default"
                onClick={() => { reset({}) }}
            >
                Reset
                  </Button>
            <Button
                type="submit"
                variant="contained"
                color="primary"
            >
                Save
                  </Button>
      </form>
    );
}

Answer 1

您可以链接到有效的示例吗？这可能有助于调试，但是仅通过阅读代码，如果您在useEffect调用中添加了这些依赖项，这些警告似乎就可以解决。例如：

/* CustomerForm */

useEffect(() => {
  if (customer) {
    setValue("firstName", customer.firstName);
    setValue("lastName", customer.lastName);
    setValue("phoneNumber", customer.phoneNumber);
    setValue("email", customer.email);
  }
},[customer, loadData, setValue]);

Answer 2

您可以添加缺少的依赖项，例如

useEffect(() => {
if (customer) {
        setValue("firstName", customer.firstName);
        setValue("lastName", customer.lastName);
        setValue("phoneNumber", customer.phoneNumber);
        setValue("email", customer.email);
    }
 },[customer,setValue,loadData]);

但是在某些情况下，将方法添加为依赖项会导致无限次重新渲染，因此我认为克服警告的最佳方法是通过

禁用它

    useEffect(() => {
if (customer) {
        setValue("firstName", customer.firstName);
        setValue("lastName", customer.lastName);
        setValue("phoneNumber", customer.phoneNumber);
        setValue("email", customer.email);
    }
 //eslint-disable-next-line
 },[customer]);

为什么在React.js中使用useEffect钩子时收到这些警告？

2 个答案: