Javascript React数据网格(adazzle):渲染未返回任何内容。这通常意味着缺少返回语句。或者,要不呈现任何内容,请返回null
我是React新手,我使用adazzle的React数据网格,axios从Web服务返回数据。但是,我收到一条错误消息:“render未返回任何内容。这通常意味着缺少返回语句。或者,若要不呈现任何内容,请返回null”。请帮忙 这是我的密码: App.jsJavascript React数据网格(adazzle):渲染未返回任何内容。这通常意味着缺少返回语句。或者,要不呈现任何内容,请返回null,javascript,reactjs,react-native,Javascript,Reactjs,React Native,我是React新手,我使用adazzle的React数据网格,axios从Web服务返回数据。但是,我收到一条错误消息:“render未返回任何内容。这通常意味着缺少返回语句。或者,若要不呈现任何内容,请返回null”。请帮忙 这是我的密码: App.js import React, {useState, useEffect} from "react"; import ReactDOM from "react-dom"; import ReactDataG
import React, {useState, useEffect} from "react";
import ReactDOM from "react-dom";
import ReactDataGrid from "react-data-grid";
export default function App() {
const [isLoaded,setIsLoaded] = useState(false);
const [rowData,setRowData] = useState([]);
useEffect(() => {
const axios = require('axios').default;
axios
.get('http://localhost:8080/user/all') // Java Springboot users REST service
.then((response) => {
setIsLoaded(true);
setRowData(response.data);
response.data.forEach(user => {
});
});
}, []);
const columns = [
{ key: "_id", name: "_id", width: 250 },
{ key: "id", name: "ID", width: 100 },
{ key: "userName", name: "User Name", width: 250, editable: true, enableCellSelect: true },
{ key: "userTelNo", name: "Tel No", width: 250, editable: true, enableCellSelect: true },
{ key: "userEmail", name: "EMail", width: 250, editable: true, enableCellSelect: true },
{ key: "userRole", name: "Role", width: 150, editable: true, enableCellSelect: true },
{ key: "dateSaved", name: "Date Saved", width: 250 },
];
const rows = [
{ id: 0, userName: "Task 1", userEmail: "test email" }
];
class Example extends React.Component {
state = { rows };
onGridRowsUpdated = ({ fromRow, toRow, updated }) => {
this.setState(state => {
const rows = state.rows.slice();
for (let i = fromRow; i <= toRow; i++) {
rows[i] = { ...rows[i], ...updated };
}
return { rows };
});
};
render() {
return (
<ReactDataGrid
columns={columns}
rowGetter={i => this.state.rows[i]}
rowsCount={3}
onGridRowsUpdated={this.onGridRowsUpdated}
enableCellSelect={true}
/>
);
}
}
const rootElement = document.getElementById("root");
ReactDOM.render(<Example />, rootElement);
}
import React,{useState,useffect}来自“React”;
从“react dom”导入react dom;
从“react数据网格”导入ReactDataGrid;
导出默认函数App(){
const[isLoaded,setIsLoaded]=useState(false);
const[rowData,setRowData]=useState([]);
useffect(()=>{
const axios=require('axios')。默认值;
axios
.get('http://localhost:8080/user/all')//Java Springboot用户REST服务
。然后((响应)=>{
setIsLoaded(真);
setRowData(response.data);
response.data.forEach(用户=>{
});
});
}, []);
常量列=[
{键:“_id”,名称:“_id”,宽度:250},
{键:“id”,名称:“id”,宽度:100},
{键:“用户名”,名称:“用户名”,宽度:250,可编辑:true,enableCellSelect:true},
{key:“userTelNo”,name:“telno”,宽度:250,可编辑:true,enableCellSelect:true},
{key:“userEmail”,name:“EMail”,宽度:250,可编辑:true,enableCellSelect:true},
{key:“userRole”,name:“Role”,宽度:150,可编辑:true,enableCellSelect:true},
{键:“dateSaved”,名称:“Date Saved”,宽度:250},
];
常量行=[
{id:0,用户名:“任务1”,用户电子邮件:“测试电子邮件”}
];
类示例扩展了React.Component{
状态={rows};
onGridRowsUpdated=({fromRow,toRow,updated})=>{
this.setState(state=>{
const rows=state.rows.slice();
for(让i=fromRow;i
);
}
}
const rootElement=document.getElementById(“根”);
render(,rootElement);
}
index.js
import React from 'react';
import ReactDOM from 'react-dom';
import App from './App';
ReactDOM.render(<App />, document.querySelector('#root'));
从“React”导入React;
从“react dom”导入react dom;
从“./App”导入应用程序;
ReactDOM.render(,document.querySelector('#root');
您的导出默认函数App()
不返回任何内容。您不能在组件内部调用ReactDOM.render()
。ReactDOM.render(,document.querySelector('#root');
是您需要的对ReactDOM的唯一调用。