react-hook-form：使用 onBlur 模式时验证不起作用

我正在尝试显示错误yup and react-hook-form当用户选择超过 5 个复选框但未成功时。

相反，当选择第七个复选框时会显示错误。

这是简化的代码：

imports...

const schema = yup.object().shape({
  option: yup.array().max(5)
});
function App() {
  const { register, handleSubmit, errors } = useForm({
    mode: "onBlur",
    resolver: yupResolver(schema)
  });

  const [state, setState] = useState({
    wasSubmitted: false
  });

  const submit = async (data) => {
    window.alert(JSON.stringify(data));
  };

  if (state.wasSubmitted) {
    return <p>Congrats</p>;
  } else {
    return (
      <>
        <CssBaseline />
        <Container maxWidth="sm">
          <Typography variant="h2" component="h1">
            My form
          </Typography>
          <form noValidate autoComplete="off" onSubmit={handleSubmit(submit)}>
            <FormControl
              component="fieldset"
              error={!!errors.option}
            >
              <FormLabel component="legend">
                Please select the category or categories of books the child is
                interested in:
              </FormLabel>
              <FormGroup>
                <FormControlLabel
                  control={<Checkbox name="option" inputRef={register} />}
                  value="Option1"
                  label="Option 1"
                />
                <FormControlLabel
                  control={<Checkbox name="option" inputRef={register} />}
                  value="Option2"
                  label="Option 2"
                />
                <FormControlLabel
                  control={<Checkbox name="option" inputRef={register} />}
                  label="Option3"
                  value="Option 3"
                />
                <FormControlLabel
                  control={<Checkbox name="option" inputRef={register} />}
                  value="Option4"
                  label="Option 4"
                />
                <FormControlLabel
                  control={<Checkbox name="option" inputRef={register} />}
                  value="Option5"
                  label="Option 5"
                />
                <FormControlLabel
                  control={<Checkbox name="option" inputRef={register} />}
                  value="Option6"
                  label="Option 6"
                />
                <FormControlLabel
                  control={<Checkbox name="option" inputRef={register} />}
                  value="Option7"
                  label="Option 7"
                />
                <FormControlLabel
                  control={<Checkbox name="option" inputRef={register} />}
                  value="Option8"
                  label="Option 8"
                />
                <FormControlLabel
              <FormHelperText>Up to five categories</FormHelperText>
            </FormControl>

            <Button
              type="submit"
              disableElevation
            >
              Submit
            </Button>
          </form>
        </Container>
      </>
    );
  }
}

export default App;

您还可以在这里找到该项目的沙箱：

有任何想法吗？

正如@aadlc所说，解决方案是将模式设置为onChange or all。我会解释原因。

来自react-hook-formAPI docs https://react-hook-form.com/api:

mode: onChange | onBlur | onSubmit | onTouched | all = 'onSubmit'

在您的代码中，表单模式是onBlur。这意味着验证被触发blur事件（取消输入焦点）。当您选择该选项时n+1，它触发选项的模糊事件n.

例如就在您选择第 6 个选项（无效）之前，blur事件从第 5 个选项（有效）触发，因为您不再关注它，并从选项 1-5 进行验证，因此您必须检查第 7 个选项以重新验证从 1 到 6 的选项。

-- select up to 5 options --
select option 4

blur event fires from option 4 -> validate -> pass
select option 5

blur event fires from option 5 -> validate -> pass
select option 6

blur event fires from option 6 -> validate -> fail
select option 7

将验证模式更改为onChange将验证after change当所有值都是最新时，事件被触发：

-- select up to 5 options --
select option 4

blur event fires from option 4
select option 5
change event fires from option 5 -> validate -> pass

blur event fires from option 5
select option 6
change event fires from option 6 -> validate -> fail

blur event fires from option 6
select option 7
change event fires from option 7 -> validate -> fail

将验证模式更改为all将验证两者blur and change事件，这在此工作流程中可能有点过分，但它也有效。