React-如何在react中显示make objects loop

Question

这是我尝试过的

episode.js

import Parser from "rss-parser";
import React from "react";

export default function Episode() {
  
const parser = new Parser();
const url1 = "https://anchor.fm/s/75abc654/podcast/rss";
const [data, setData] = React.useState({});
 
 (async  () => {
    let data = await parser.parseURL(url1);
  setData(data);
   // console.log(data.title)
   // data.items.forEach((item) => {
      // console.log(item.title)
      //console.log(item.pubDate.slice(5, 17))
      //console.log(item.enclosure.url)
      // console.log(item.itunes.image)
    });
  })();
return(
  <h1>{item.title}</h1>

  {data.items.map((item, index)=>{
  return(
     <h1>{item.title}</h1>
   )})}

)

}

并且输出是黑屏..控制台没有错误..帮助我从 rss 提要中获取数据而没有黑屏

Answer 1

只需用这样的 useEffect 挂钩替换您的异步函数

useEffect(() => {
  async function fetchMyAPI() {
    let data = await parser.parseURL(url1);
    setData(data);
    // console.log(data.title)
    // data.items.forEach((item) => {
    // console.log(item.title)
    //console.log(item.pubDate.slice(5, 17))
    //console.log(item.enclosure.url)
    // console.log(item.itunes.image)
  }
  fetchMyAPI();
}, []);

每当您的组件加载到屏幕上时，这将执行一次

同时将 data.item.map 更改为

{data.items?.map((item, index) => {
    return <h1>{item.title}</h1>;
 })}

否则会在第一次渲染时抛出错误

Answer 2

您正在无限期地调用 async 方法！您需要在组件首次渲染时通过 useEffect 调用一次：

import Parser from "rss-parser"; 
import React, { useEffect } from "react";

function Episode() {
  const parser = new Parser();
  const url1 = "https://anchor.fm/s/75abc654/podcast/rss";
  const [data, setData] = React.useState({});

  useEffect(() => {
    (async () => {
      let data = await parser.parseURL(url1);
      console.log(data);
      setData(data);
    })();
  }, []);

  return (
    <>
      {data.items?.map((item, index) => (
        <h1>{item.title}</h1>
      ))}
    </>
  );
}
export default function App() {
  return <Episode />;
}

React-如何在react中显示make objects loop

React-How to display make objects loop in react

javascript

reactjs

xml

rss