Reactjs 使用钩子状态的数组反应无限滚动
在我的react组件中设置Reactjs 使用钩子状态的数组反应无限滚动,reactjs,react-infinite-scroll-component,react-infinite-scroll,Reactjs,React Infinite Scroll Component,React Infinite Scroll,在我的react组件中设置react infinite scroller时遇到问题 import React, { useEffect, useState } from 'react'; import InfiniteScroll from 'react-infinite-scroller'; export default function ProductHistory() { const [dbScans, setDbScans] = useState<IProductClient
react infinite scroller
时遇到问题
import React, { useEffect, useState } from 'react';
import InfiniteScroll from 'react-infinite-scroller';
export default function ProductHistory() {
const [dbScans, setDbScans] = useState<IProductClient[]>([]);
const [loadedProducts, setLoadedProducts] = useState([]);
useEffect(() => {
(async function getDataFromDB() {
setDbScans(await db.yourScans.toArray());
})();
}, []);
let productHistory = dbScans;
// This function is not working
const loadProducts = (page: number) => {
const perPage = 3;
const moreItems: any = dbScans.slice(
page * perPage - perPage,
page * perPage + 1
);
// Am I doing this right?
setLoadedProducts(loadedProducts.concat(moreItems));
}
return (
<>
<div className="product-history">
{ productHistory.length > 0 ?
<InfiniteScroll
pageStart={0}
loadMore={loadProducts(0)} // This is not working
hasMore={true}
loader={<div className="loader" key={0}>Loading ...</div>}
>
{productHistory.map((product: any) =>
<div className="product-history__item" key={product.id}>
<p>{product.name}
</div>
)}
</InfiniteScroll>
: ''
}
</div>
</>
)
}
我不想通过API直接在我的组件中使用loadMore
获取数据,因为我已经从IndexedDB获取了数据
因此,我想使用我的数组dbScans
(带对象的数组),并希望具有最多3个数组项的无限滚动
我试图创建一个loadProducts
函数来切片和浓缩我想要渲染的数组,但是当我试图在无限滚动组件中调用它时,我遇到了重载错误
import React, { useEffect, useState } from 'react';
import InfiniteScroll from 'react-infinite-scroller';
export default function ProductHistory() {
const [dbScans, setDbScans] = useState<IProductClient[]>([]);
const [loadedProducts, setLoadedProducts] = useState([]);
useEffect(() => {
(async function getDataFromDB() {
setDbScans(await db.yourScans.toArray());
})();
}, []);
let productHistory = dbScans;
// This function is not working
const loadProducts = (page: number) => {
const perPage = 3;
const moreItems: any = dbScans.slice(
page * perPage - perPage,
page * perPage + 1
);
// Am I doing this right?
setLoadedProducts(loadedProducts.concat(moreItems));
}
return (
<>
<div className="product-history">
{ productHistory.length > 0 ?
<InfiniteScroll
pageStart={0}
loadMore={loadProducts(0)} // This is not working
hasMore={true}
loader={<div className="loader" key={0}>Loading ...</div>}
>
{productHistory.map((product: any) =>
<div className="product-history__item" key={product.id}>
<p>{product.name}
</div>
)}
</InfiniteScroll>
: ''
}
</div>
</>
)
}
import React,{useffect,useState}来自“React”;
从“react infinite scroller”导入InfiniteScroll;
导出默认函数ProductHistory(){
const[dbScans,setDbScans]=useState([]);
const[loadedProducts,setLoadedProducts]=useState([]);
useffect(()=>{
(异步函数getDataFromDB(){
setDbScans(wait db.yourScans.toArray());
})();
}, []);
让productHistory=dbScans;
//此功能不起作用
const loadProducts=(页码)=>{
每页常数=3;
const moreItems:any=dbScans.slice(
每页*每页-每页,
页码*每页+1
);
//我这样做对吗?
setLoadedProducts(loadedProducts.concat(更多项));
}
返回(
{productHistory.length>0?
{productHistory.map((产品:any)=>
{product.name}
)}
: ''
}
)
}
您应该引入一个名为lastObjectPosition的状态变量,该变量将具有无限滚动显示的最后一个对象的位置
const perPage = 3;
const [lastObjectPosition , setLastObjectPosition ] = useState(0);
然后hasMore属性应设置如下:
hasMore={lastObjectPosition < dbScans.length}
谢谢你的回答和帮助!您能告诉我currentProducts是什么并且将用于什么吗?currentProducts是我给出的名称。你可以叫它任何东西。可能是,当前值?它指的是loadedProducts中存在的值。非常抱歉,即使在您的帮助下,我也无法解决我的问题。由于代码已更改,我创建了一个新问题,并提到您已经帮助我解决了问题!供参考: