在React.js中向下滚动页面时如何加载更多搜索结果? [英] How to load more search results when scrolling down the page in React.js?
问题描述
向下滚动页面时,我想加载更多搜索结果. 我使用google API书籍,并且只想加载10个搜索结果,并且如果用户滚动到最后一个搜索元素,则自动加载下一个10个搜索结果.怎么做?我需要一个代码示例,正确的解决方案应该是什么样子.感谢您的帮助.
I would like to load more searching results when scrolling down the page. I work with google API book and I would like to load just 10 searching results and if user scroll to the last search element than next 10 results load automatically. How to do that? I need a code example how proper solution should look like. Thanks for help.
我的App.js文件如下:
My App.js file is as follow:
import React, { useState } from "react";
import axios from "axios";
import './App.css';
import 'bootstrap/dist/css/bootstrap.min.css';
const App = () => {
const [searchTerm, setSearchTerm] = useState("");
const [books, setBooks] = useState({ items: [] });
const onInputChange = e => {
setSearchTerm(e.target.value);
};
let API_URL = 'https://www.googleapis.com/books/v1/volumes';
const fetchBooks = async () => {
if (document.getElementById("choose_search").value === "title") {
const result = await axios.get(`${API_URL}?
q=${searchTerm}&maxResults=40`);
setBooks(result.data);
}
else {
const result = await axios.get(`${API_URL}?
q=inauthor:${searchTerm}&maxResults=40`);
setBooks(result.data);
}
};
const onSubmitHandler = e => {
e.preventDefault();
fetchBooks();
};
return (
<section>
<form onSubmit={onSubmitHandler} id="submit">
<label>
<input
type="search"
placeholder="Search books"
value={searchTerm}
onChange={onInputChange}
/>
<button type="submit" class="btn btn-
success">Search</button>
</label>
</form>
<div id="choose_position" class="row">
<div class="col-2">
<select id="choose_search" class="form-control-sm">
<option value="" disabled selected>Select search
type</option>
<option value="title">Title</option>
<option value="author">Author</option>
</select>
</div>
</div>
<ul>
{books.items.map((book, index) => {
return (
<div>
<div class="border rounded">
<div class="row">
<div class="col-12 d-flex justify-content-
center p-4" >
<u><h5>{book.volumeInfo.title}</h5></u>
</div>
</div>
<div class="row">
<div class="col-4">
<img
id="img_book"
alt={`${book.volumeInfo.title} book`}
src=
{`http://books.google.com/books/content?id=${
book.id
}&printsec=frontcover&img=1&zoom=1&source=gbs_api`}
/>
</div>
<div class="col-8">
{typeof book.volumeInfo.description ===
'string' && book.volumeInfo.description.length > 0 ?
book.volumeInfo.description : <img src="../no_description.jpg"
id="description_img"/>}
</div>
</div>
<div class="row">
<div class="col-4"></div>
<div class="col-4"><b>Preview:</b> {typeof
book.volumeInfo.previewLink === 'string' &&
book.volumeInfo.previewLink.length > 0 ? <a href=
{book.volumeInfo.previewLink}>Link</a> : 'No data'}
</div>
<div class="col-4"><b>Published date:</b>
{typeof book.volumeInfo.publishedDate === 'string' &&
book.volumeInfo.publishedDate.length > 0 ? book.volumeInfo.publishedDate
: 'No data'}
</div>
</div>
<div class="row pb-3">
<div class="col-4"></div>
<div class="col-4"><b>Free download:</b>
{typeof book.accessInfo.pdf.downloadLink === 'string' &&
book.accessInfo.pdf.downloadLink.length > 0 ? <a href=
{book.accessInfo.pdf.downloadLink}>Link</a> : 'Not avaliable'}
</div>
<div class="col-4"><b>Ebook version:</b>
{typeof book.saleInfo.isEbook === 'boolean' && book.saleInfo.isEbook ===
true ? 'Yes' : 'No'}
</div>
<br/>
</div>
</div><br/>
</div>
);
})}
</ul>
</section>
);
};
export default App;
推荐答案
这称为无限滚动. 如果您不想从头开始构建它,则可以使用外部库:
This is called infinite scroll. If you don't wanna build this from the scratch, you can use external libs:
https://www.npmjs.com/package/react-infinite-scroller
https://www.npmjs.com/package/react-infinite-滚动组件
如果您想自己构建它,可以按照以下教程进行:
If you wanna build it yourself, you can follow these tutorials:
https://alligator.io/react/react-infinite-scroll/
https://upmostly. com/tutorials/build-in-infinite-scroll-component-in-react-using-react-hooks
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