使用React从API获取后未填充结果

import React, { useState, useEffect } from 'react';

function DataFetchingComponent() {
  const [data, setData] = useState(null);
  const [loading, setLoading] = useState(true);
  const [error, setError] = useState(null);

  useEffect(() => {
    let isMounted = true; // 添加一个标志来跟踪组件的挂载状态

    const fetchData = async () => {
      try {
        const response = await fetch('https://api.example.com/data');
        if (!response.ok) {
          throw new Error('Network response was not ok');
        }
        const result = await response.json();
        if (isMounted) {
          setData(result); // 确保组件仍然挂载时才更新状态
        }
      } catch (err) {
        if (isMounted) {
          setError(err); // 同样，确保在组件挂载时设置错误状态
        }
      } finally {
        if (isMounted) {
          setLoading(false); // 完成后更新加载状态
        }
      }
    };

    fetchData();

    return () => {
      isMounted = false; // 清理函数，组件卸载时设置为false
    };
  }, []); // 空依赖数组确保只在组件挂载时执行一次

  if (loading) return <div>Loading...</div>;
  if (error) return <div>Error: {error.message}</div>;

  return (
    <div>
      {data ? (
        <ul>
          {data.map(item => (
            <li key={item.id}>{item.name}</li>
          ))}
        </ul>
      ) : (
        <div>No data available</div>
      )}
    </div>
  );
}

export default DataFetchingComponent;