const username= document.querySelector('#username');
const submit=document.querySelector('#submit');

submit.addEventListener('click',()=>{
    if(username.validity.typeMismatch){
        username.setCustomValidity('Please enter User Name');
    }else{
        username.setCustomValidity('');
    }
if(pass.validity.typeMismatch){
        pass.setCustomValidity('Please enter Password');
    }else{
        pass.setCustomValidity('');
    }

})

下面是在HTML5中处理自定义错误消息的代码:

<input type="text" id="username" required placeholder="Enter Name" oninvalid = "。setCustomValidity('在这里输入用户名')" oninput = " this.setCustomValidity (")" / >

这部分很重要，因为它隐藏了用户输入新数据时的错误消息:

oninput="this.setCustomValidity('')"

可以通过在字段中添加'title'来轻松处理:

<input type="text" id="username" required title="This field can not be empty"  />

const username= document.querySelector('#username');
const submit=document.querySelector('#submit');

submit.addEventListener('click',()=>{
    if(username.validity.typeMismatch){
        username.setCustomValidity('Please enter User Name');
    }else{
        username.setCustomValidity('');
    }
if(pass.validity.typeMismatch){
        pass.setCustomValidity('Please enter Password');
    }else{
        pass.setCustomValidity('');
    }

})

解决方案防止谷歌Chrome错误消息输入每个符号:

<p>Click the 'Submit' button with empty input field and you will see the custom error message. Then put "-" sign in the same input field.</p> <form method="post" action="#"> <label for="text_number_1">Here you will see browser's error validation message on input:</label><br> <input id="test_number_1" type="number" min="0" required="true" oninput="this.setCustomValidity('')" oninvalid="this.setCustomValidity('This is my custom message.')"/> <input type="submit"/> </form> <form method="post" action="#"> <p></p> <label for="text_number_1">Here you will see no error messages on input:</label><br> <input id="test_number_2" type="number" min="0" required="true" oninput="(function(e){e.setCustomValidity(''); return !e.validity.valid && e.setCustomValidity(' ')})(this)" oninvalid="this.setCustomValidity('This is my custom message.')"/> <input type="submit"/> </form>

根据Salar对JSX和React的回答，我注意到React选择的行为并不像<input/>字段有关验证。显然，需要一些变通方法来只显示自定义消息，并避免在不方便的时候显示它。

我在这里提出了一个问题，如果有帮助的话。下面是一个code andbox的工作示例，其中最重要的代码复制在这里:

Hello.js

import React, { Component } from "react";
import SelectValid from "./SelectValid";

export default class Hello extends Component {
  render() {
    return (
      <form>
        <SelectValid placeholder="this one is optional" />
        <SelectValid placeholder="this one is required" required />
        <input
          required
          defaultValue="foo"
          onChange={e => e.target.setCustomValidity("")}
          onInvalid={e => e.target.setCustomValidity("foo")}
        />
        <button>button</button>
      </form>
    );
  }
}

SelectValid.js

import React, { Component } from "react";
import Select from "react-select";
import "react-select/dist/react-select.css";

export default class SelectValid extends Component {
  render() {
    this.required = !this.props.required
      ? false
      : this.state && this.state.value ? false : true;
    let inputProps = undefined;
    let onInputChange = undefined;
    if (this.props.required) {
      inputProps = {
        onInvalid: e => e.target.setCustomValidity(this.required ? "foo" : "")
      };
      onInputChange = value => {
        this.selectComponent.input.input.setCustomValidity(
          value
            ? ""
            : this.required
              ? "foo"
              : this.selectComponent.props.value ? "" : "foo"
        );
        return value;
      };
    }
    return (
      <Select
        onChange={value => {
          this.required = !this.props.required ? false : value ? false : true;
          let state = this && this.state ? this.state : { value: null };
          state.value = value;
          this.setState(state);
          if (this.props.onChange) {
            this.props.onChange();
          }
        }}
        value={this && this.state ? this.state.value : null}
        options={[{ label: "yes", value: 1 }, { label: "no", value: 0 }]}
        placeholder={this.props.placeholder}
        required={this.required}
        clearable
        searchable
        inputProps={inputProps}
        ref={input => (this.selectComponent = input)}
        onInputChange={onInputChange}
      />
    );
  }
}