Arrays “单击时不更新图像数组的状态”事件
我有一个图像网格填充了一个无头CMS的背景。当用户单击其中一个图像时,它们将被带到图像幻灯片中 我需要能够在网格中点击图像的索引处打开图像幻灯片Arrays “单击时不更新图像数组的状态”事件,arrays,reactjs,react-hooks,Arrays,Reactjs,React Hooks,我有一个图像网格填充了一个无头CMS的背景。当用户单击其中一个图像时,它们将被带到图像幻灯片中 我需要能够在网格中点击图像的索引处打开图像幻灯片 import React, { useState, useEffect, useRef } from "react"; import { css, jsx } from "@emotion/core"; import ImageSliderContent from "./ImageSliderConte
import React, { useState, useEffect, useRef } from "react";
import { css, jsx } from "@emotion/core";
import ImageSliderContent from "./ImageSliderContent";
import styles from "./LocationsImageGallery.module.css";
import ImageGrid from "./ImageGrid";
import ImageSlide from "./ImageSlide";
import Arrow from "./Arrow";
import Dots from "./Dots";
import imageUrlBuilder from "@sanity/image-url";
import client from "../../client";
const builder = imageUrlBuilder(client);
const LocationsImageGallery = (props) => {
const { caption, image } = props;
const images = props.image;
const [state, setState] = useState({
translate: 0,
transition: 0.45,
activeSlide: 0,
});
const [showSlider, setShowSlider] = useState(false);
const [showGrid, setShowGrid] = useState(true);
const { translate, transition, activeSlide, _slides } = state;
const size = useWindowSize();
const transitionRef = useRef();
function useWindowSize() {
const isClient = typeof window === "object";
function getSize() {
return {
width: isClient ? window.innerWidth : undefined,
};
}
const [windowSize, setWindowSize] = useState(getSize);
useEffect(() => {
if (!isClient) {
return false;
}
function handleResize() {
setWindowSize(getSize());
}
window.addEventListener("resize", handleResize);
return () => window.removeEventListener("resize", handleResize);
}, []);
return windowSize;
}
const nextSlide = () => {
if (activeSlide === images.length - 1) {
return setState({
...state,
translate: 0,
activeSlide: 0,
});
}
setState({
...state,
activeSlide: activeSlide + 1,
translate: (activeSlide + 1) * size.width,
});
};
const prevSlide = () => {
if (activeSlide === 0) {
return setState({
...state,
translate: (images.length - 1) * size.width,
activeSlide: images.length - 1,
});
}
setState({
...state,
activeSlide: activeSlide - 1,
translate: (activeSlide - 1) * size.width,
});
};
const show = (index) => {
setShowGrid(false);
setShowSlider(true);
setState({ activeSlide: index });
console.log(activeSlide, index, state);
};
const hide = () => {
setShowSlider(false);
setShowGrid(true);
};
return (
<div className={styles.root}>
<div className={styles.header}>
<a href="/locations">X</a>
</div>
{showGrid && (
<div className={styles.imageGrid}>
<div className={styles.imageGridContainer}>
{images.map((image, index, caption) => (
<div className={styles.imageContainer} onClick={() => show(index)}>
<img
src={builder.image(image).auto("format").width(2000).url()}
className={styles.image}
alt={image.caption}
key={index}
/>
<p className={styles.caption}>{image.caption}</p>
</div>
))}
</div>
</div>
)}
{showSlider && (
<div className={styles.imageGalleryContainer}>
<div className={styles.imageSlider}>
<ImageSliderContent
translate={translate}
transition={transition}
width={size.width * images.length}
>
{images.map((image, index, caption) => (
<>
<ImageSlide
key={image + index}
content={builder.image(image).auto("format").url()}
></ImageSlide>
</>
))}
</ImageSliderContent>
<Arrow direction="left" handleClick={prevSlide} />
<Arrow direction="right" handleClick={nextSlide} />
</div>
<div className={styles.infoBar}>
<p className={styles.infoCaption}>
Locations / <span>{image.caption}</span>
</p>
<a href="" onClick={hide} className={styles.infoThumbnails}>
Show Thumbnails
</a>
</div>
</div>
)}
</div>
);
};
export default LocationsImageGallery;
import React,{useState,useffect,useRef}来自“React”;
从“@emotion/core”导入{css,jsx};
从“/ImageSliderContent”导入ImageSliderContent;
从“/LocationsImageGallery.module.css”导入样式;
从“/ImageGrid”导入ImageGrid;
从“/ImageSlide”导入ImageSlide;
从“/Arrow”导入箭头;
从“/Dots”导入点;
从“@sanity/image url”导入imageUrlBuilder;
从“../../client”导入客户端;
const builder=imageUrlBuilder(客户端);
const LocationsImageGallery=(道具)=>{
const{caption,image}=props;
const images=props.image;
常量[状态,设置状态]=使用状态({
翻译:0,
过渡:0.45,
动态幻灯片:0,
});
常量[showSlider,setShowSlider]=useState(false);
const[showGrid,setShowGrid]=useState(true);
const{translate,transition,activeSlide,_slides}=state;
常量大小=UseWindowsSize();
const transitionRef=useRef();
函数useWindowsSize(){
const isClient=typeof window==“object”;
函数getSize(){
返回{
宽度:isClient?窗口。内部宽度:未定义,
};
}
const[windowSize,setWindowSize]=useState(getSize);
useffect(()=>{
如果(!isClient){
返回false;
}
函数handleResize(){
setWindowsSize(getSize());
}
addEventListener(“调整大小”,handleResize);
return()=>window.removeEventListener(“resize”,handleResize);
}, []);
返回窗口大小;
}
常量nextSlide=()=>{
如果(activeSlide==images.length-1){
返回设置状态({
……国家,
翻译:0,
动态幻灯片:0,
});
}
设定状态({
……国家,
activeSlide:activeSlide+1,
平移:(活动幻灯片+1)*size.width,
});
};
常数prevside=()=>{
如果(活动幻灯片===0){
返回设置状态({
……国家,
翻译:(images.length-1)*size.width,
activeSlide:images.length-1,
});
}
设定状态({
……国家,
activeSlide:activeSlide-1,
平移:(活动幻灯片-1)*size.width,
});
};
常量显示=(索引)=>{
设置显示网格(假);
设置显示滑块(真);
setState({activeSlide:index});
日志(activeSlide、索引、状态);
};
常量隐藏=()=>{
设置显示滑块(假);
设置显示网格(真);
};
返回(
{showGrid&&(
{images.map((图像、索引、标题)=>(
显示(索引)}>
{image.caption}
))}
)}
{showsslider&&(
{images.map((图像、索引、标题)=>(
))}
)}
);
};
导出默认位置SimageGallery;
此时,活动幻灯片和索引都被正确地传递给函数。但是,处于状态的activeSlide不会更新
如果我使用console.log(activeSlide、index、state),我会得到
0.5{translate:0,transition:0.45,activeSlide:0}
设置状态是异步的,如果要立即更改,请在设置状态中使用回调函数
setState({ activeSlide: index }, () => {});
这里有两个(甚至更多)主要的bug,一个是您记录了一个过时的状态,因为
第二个是setState
的useState
钩子,不合并状态,所以这样的代码:setState({activeSlide:index})
实际上会覆盖其他状态值:{translate,activeSlide,…}
通常,在这种情况下,您需要使用:
setState
是异步的,所以console.log(activeSlide,index,state)代码>在设置状态之后
不会一直是你认为应该读的代码!!!!请删除不重要的行以便于理解。谢谢!不幸的是,这将导致每次重新渲染和内部服务器错误问题是关于使用useState
hook的功能组件useState
没有可选的回调函数,因此这不起作用。哎呀,你说得对,我没有抓住要点。我没有读所有的代码,只是读了那一行,觉得setState就像我们以前的this.setState()
。谢谢你,我仍然在努力学习钩子。我可以看出这是功能更新的正确方法,但是它似乎仍然没有更新activeSlide。因此,无论单击哪个索引,my console.log都会显示为activeSlide:0。您应该制作一个可复制的示例,这样的代码太长,无法理解,请阅读
const show = (index) => {
setShowGrid(false);
setShowSlider(true);
setState((prev) => {
console.log(prev);
return { ...prev, activeSlide: index };
});
};