Javascript 在react钩子中执行之前正在更新的状态
我正在开发一个表单,它使用HOC获取输入(来自用户的多个图像和文本)。 下面是我的表单组件Javascript 在react钩子中执行之前正在更新的状态,javascript,reactjs,frontend,react-hooks,Javascript,Reactjs,Frontend,React Hooks,我正在开发一个表单,它使用HOC获取输入(来自用户的多个图像和文本)。 下面是我的表单组件 import React from "react"; import Grid from "@material-ui/core/Grid"; import Typography from "@material-ui/core/Typography"; import Alert from "@material-ui/lab/Alert"; import TextField from "@material-ui
import React from "react";
import Grid from "@material-ui/core/Grid";
import Typography from "@material-ui/core/Typography";
import Alert from "@material-ui/lab/Alert";
import TextField from "@material-ui/core/TextField";
import FormControlLabel from "@material-ui/core/FormControlLabel";
import { Snackbar, IconButton } from "@material-ui/core";
import { Loading, Snackbars, UIButton, UITextField } from "../UI/index";
import {
Paper,
makeStyles,
Button,
} from "@material-ui/core";
function Gallery(props) {
let {
submitHandler,
selectImages,
message,
galleryForm,
inputChangedHandler,
} = props;
return (
<div>
<Paper
elevation={3}
style={{ padding: "20px" }}
>
<form
onSubmit={submitHandler}
noValidate
id="galleryForm"
>
<Grid container spacing={3}>
<Grid item xs={12} md={6}>
<UITextField
name="imageTitle"
label="Image Title"
value={galleryForm.imageTitle.value}
onChange={(event) => inputChangedHandler(event, "imageTitle")}
error={galleryForm.imageTitle.invalid}
helperText={galleryForm.imageTitle.helperText}
/>
</Grid>
<Grid item xs={12} sm={6}>
<Grid container>
<Grid>
<TextField
id="standard-basic"
fullWidth
label="Select File To Upload"
value={message}
error={galleryForm.images.invalid}
helperText={galleryForm.images.helperText}
/>
</Grid>
<Grid>
<input
accept=".jpg , .png, .jpeg"
className={classes.input}
style={{ display: "none" }}
id="raised-file"
multiple
type="file"
onChange={selectImages}
/>
<label htmlFor="raised-file">
<Button
variant="contained"
style={{
background: "#D3D3D3",
color: "black",
fontSize: "15px",
borderRedius: "4px",
}}
component="span"
>
UPLOAD PHOTOS
</Button>
</label>
</Grid>
</Grid>
</Grid>
<Grid className={classes.center}>
<UIButton
type="submit"
variant="contained"
color="primary"
size="large"
className={classes.submit}
>
create gallery
</UIButton>
</Grid>
</Grid>
</form>
</Paper>
</div>
);
}
export default enhancer(Gallery);
从“React”导入React;
从“@material ui/core/Grid”导入网格;
从“@material ui/core/Typography”导入排版;
从“@material ui/lab/Alert”导入警报;
从“@material ui/core/TextField”导入TextField;
从“@material ui/core/FormControlLabel”导入FormControlLabel;
从“@material ui/core”导入{Snackbar,IconButton}”;
从“./UI/index”导入{Loading,snackbar,UIButton,UITextField};
进口{
纸张
制作风格,
按钮
}来自“@材料界面/核心”;
功能画廊(道具){
让{
服从者,
选择图像,
消息
厨房式,
inputChangedHandler,
}=道具;
返回(
inputChangedHandler(事件,“imageTitle”)}
错误={galleryForm.imageTitle.invalid}
helperText={galleryForm.imageTitle.helperText}
/>
上传照片
创建图库
);
}
导出默认增强器(库);
下面是我的HOC(增强器),它接受Gallery组件
import React, { useEffect, useState } from "react";
import { compose } from "redux";
import Gallery from "./index";
import galleryFiled from "./galleryField";
export let enhancer = compose((Gallery) => ({ ...props }) => {
const [galleryForm, setGalleryForm] = useState(galleryFiled);
const [message, setMessage] = useState("");
const selectImages = (event) => {
const updatedForm = {
...galleryForm,
};
console.log("check:", galleryForm);
for (var i = 0; i < event.target.files.length; i++) {
if (event.target.files.item(i).name.match(/\.(jpg|jpeg|png)$/)) {
updatedForm.images.value.push(event.target.files.item(i));
}
}
setGalleryForm({ ...updatedForm });
let message = `${updatedForm.images.value.length} valid image(s) selected`;
console.log(galleryForm);
setMessage(message);
};
const inputChangedHandler = (event, inputIdentifier) => {
const updatedForm = {
...galleryForm,
};
console.log(updatedForm);
updatedForm[inputIdentifier].value = event.target.value;
updatedForm[inputIdentifier].invalid = false;
updatedForm[inputIdentifier].helperText = "";
console.log(updatedForm);
setGalleryForm({
...updatedForm,
});
console.log(galleryForm);
};
const clearForm = (event) => {
let allFormKeys = Object.keys(galleryForm);
let formData = { ...galleryForm };
allFormKeys.forEach((formKey) => {
if (formKey == "images") {
formData[formKey].value = [];
formData[formKey].invalid = false;
formData[formKey].helperText = "";
} else {
formData[formKey].value = "";
formData[formKey].invalid = false;
formData[formKey].helperText = "";
}
});
setMessage("");
setGalleryForm(formData);
};
const submitHandler = (event) => {
event.preventDefault();
console.log("submit", galleryForm);
let updatedForm = { ...galleryForm };
console.log("update", updatedForm);
console.log("final form", galleryForm);
clearForm();
};
return (
<Gallery
{...props}
{...{
submitHandler,
selectImages,
message,
galleryForm,
inputChangedHandler,
}}
/>
);
});
export default enhancer;
import React,{useffect,useState}来自“React”;
从“redux”导入{compose};
从“/index”导入库;
从“/galleryField”导入galleryField;
导出let enhancer=compose((图库)=>({…props})=>{
const[galleryForm,setGalleryForm]=使用状态(galleryfield);
const[message,setMessage]=useState(“”);
const selectImages=(事件)=>{
const updatedForm={
…厨房式,
};
控制台日志(“检查:”,galleryForm);
对于(var i=0;i{
const updatedForm={
…厨房式,
};
console.log(updatedForm);
updatedForm[inputIdentifier].value=event.target.value;
updatedForm[inputIdentifier]。无效=false;
updatedForm[inputIdentifier].helperText=“”;
console.log(updatedForm);
集合表格({
…更新的表单,
});
控制台日志(galleryForm);
};
常量clearForm=(事件)=>{
让allFormKeys=Object.keys(galleryForm);
设formData={…galleryForm};
AllFormKey.forEach((formKey)=>{
如果(formKey==“图像”){
formData[formKey]。值=[];
formData[formKey]。无效=错误;
formData[formKey].helperText=“”;
}否则{
formData[formKey]。值=”;
formData[formKey]。无效=错误;
formData[formKey].helperText=“”;
}
});
设置消息(“”);
setGalleryForm(formData);
};
常量submitHandler=(事件)=>{
event.preventDefault();
控制台日志(“提交”,galleryForm);
让updatedForm={…galleryForm};
日志(“更新”,updatedForm);
控制台日志(“最终表格”,galleryForm);
clearForm();
};
返回(
);
});
导出默认增强器;
因此,每当我首先单击上载图像按钮时,我都会使用galleryForm的临时副本,然后在获得正确的文件后,使用selectImage按钮函数中的useState挂钩更新galleryForm
因此,我的问题是,当我最初从galleryForm的打印更新版打印galleryForm的临时副本时,即使是在功能的后期更新我的表格
与submitHandle函数面临的问题相同,clearForm函数更新galleryForm,即使我在最后调用函数,也会因此丢失表单数据,并在最初打印galleryForm后获得空表单 您正在使用spreadSyntax克隆galleryForm,但是必须注意,spread syntax只生成对象的浅拷贝。新对象中的嵌套值仍然共享引用,当您尝试更新嵌套值时,该值也会反映在原始状态中 正确的更新方法是在每个嵌套级别克隆值,如下所示
const selectImages = (event) => {
console.log("check:", galleryForm);
const imagesValue = [];
for (var i = 0; i < event.target.files.length; i++) {
if (event.target.files.item(i).name.match(/\.(jpg|jpeg|png)$/)) {
imagesValue.push(event.target.files.item(i));
}
}
// Update nested state
setGalleryForm(prevGalleryForm => ({
...prevGalleryForm,
images: {
...prevGalleryForm.images,
value: prevGalleryForm.images.concat(imagesValue)
}
}));
let message = `${imagesValue.length} valid image(s) selected`;
console.log(galleryForm);
setMessage(message);
};
const inputChangedHandler = (event, inputIdentifier) => {
const updatedForm = {
...galleryForm,
[inputIdentifier]: {
...galleryForm[inputIdentifier],
value: event.target.value,
invalid: false,
helperText:"",
}
};
console.log(updatedForm);
setGalleryForm(updatedForm);
console.log(galleryForm);
};
const clearForm = (event) => {
let allFormKeys = Object.keys(galleryForm);
let formData = { ...galleryForm };
allFormKeys.forEach((formKey) => {
if (formKey == "images") {
formData[formKey].value = [];
formData[formKey].invalid = false;
formData[formKey].helperText = "";
} else {
formData[formKey].value = "";
formData[formKey].invalid = false;
formData[formKey].helperText = "";
}
});
setMessage("");
setGalleryForm(formData);
};
const selectImages=(事件)=>{
控制台日志(“检查:”,galleryForm);
常量图像值=[];
对于(var i=0;i({
…prevGalleryForm,
图像:{
…prevGalleryForm.images,
值:prevGalleryForm.images.concat(imagesValue)
}
}));
让消息=`${imagesValue.length}选择有效图像`;
控制台日志(galleryForm);
设置消息(消息);
};
常量inputChangedHandler=(事件,inputIdentifier)=>{
const updatedForm={
…厨房式,
[输入标识符]:{
…galleryForm[inputIdentifier],
值:event.target.value,
无效:false,
helperText:“”,
}
};
console.log(updatedForm);
setGalleryForm(updatedForm);
控制台日志(galleryForm);
};
常量clearForm=(事件)=>{
让allFormKeys=Object.keys(galleryForm);
设formData={…galleryForm};
AllFormKey.forEach((formKey)=>{
如果(formKey==“图像”){