在按钮按下之前触发警报的React组件，以及在用户输入之前的POST请求

import React, { useState } from 'react';

const PostRequestForm = () => {
  const [inputValue, setInputValue] = useState('');

  const handleInputChange = (e) => {
    setInputValue(e.target.value);
  };

  const handleSubmit = (e) => {
    e.preventDefault();

    fetch('https://api.example.com/post', {
      method: 'POST',
      headers: {
        'Content-Type': 'application/json'
      },
      body: JSON.stringify({ input: inputValue })
    })
      .then(response => response.json())
      .then(data => {
        // 处理响应数据
      })
      .catch(error => {
        // 处理错误
      });
  };

  return (
    <form onSubmit={handleSubmit}>
      <input type="text" value={inputValue} onChange={handleInputChange} />
      <button type="submit">提交</button>
    </form>
  );
};

export default PostRequestForm;