reactjs 相关问题

React是一个用于构建用户界面的JavaScript库。它使用声明范式,旨在既高效又灵活。


屏幕截图捕获getDisplayMediaapi

const handleCameraClick = async (e) => { try { const stream = await navigator.mediaDevices.getDisplayMedia({ video: { cursor: 'always', displaySurface: 'window', }, audio: false, }); const video = document.createElement('video'); video.srcObject = stream; video.onloadedmetadata = () => { video.play(); const canvas = document.createElement('canvas'); canvas.width = video.videoWidth; canvas.height = video.videoHeight; const ctx = canvas.getContext('2d'); ctx.drawImage(video, 0, 0, canvas.width, canvas.height); stream.getTracks().forEach((track) => track.stop()); video.srcObject = null; canvas.toBlob((blob) => { const file = new File([blob], 'screenshot.png', { type: 'image/png', }); setFiles([file]); // setting state in react }, 'image/png'); }; } catch (err) { console.error('error capturing screen:', err); } };

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材料表:如何更改列的宽度?

我使用的是Google Material UI正式推荐为数据表库并在配置列的宽度方面正式推荐的thematerialTable

回答 6 投票 0






从字节阵列中下载blob URL在localhost中起作用,但在server

在我的NextJS/React应用程序中,我正在下载动态生成的PDF字节数组。测试应用程序时,以下片段在Localhost中正常工作。它提出了保存为对话...

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带有反应usestate钩的多个状态值 我想用React Usestate Hook设置多个状态值,以便我可以使用useffect Hook分别更新它们。我有以下代码: 导入反应,{usestate}来自“ react”; ...

import React, { useState } from "react"; const initialValues = { phone: "", email: "" }; const App = () => { const [order, setOrder] = useState(""); const [paid, setPaid] = useState(false); const [submitting, setSubmitting] = useState(false); const [loading, setLoading] = useState(false); const [data, setData] = useState(initialValues); return ( <div className="App"> </div> ); }; export default App;

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我目前正在最终确定我的reactjs -fastapi Web应用程序中的付款系统,我正在面临问题。

一些事件是异步的,不是来自前端请求(付款更新失败,试用期结束,在计费周期结束时升级等),这意味着

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当我在React应用程序中导航时,我的本地存储价值是为什么要重置的? 我正在尝试在React中浏览单击功能,以增加全局计数器并在LocalStorage中保持增加的计数器。目前,当您在同一页面上,当您通过

handleIncrement = counter => { const courses = [...this.state.courses]; //clones new arrays of counters const index = courses.indexOf(counter); // gets obj index that we receive as parameter courses[index] = {...counter}; //sets current index to new cloned counter courses[index].value++; //increments current index //console.log(this.state.counters[index]); let value = this.state.courses[0].value + this.state.courses[1].value + this.state.courses[2].value + this.state.courses[3].value + this.state.courses[4].value + this.state.courses[5].value let name1 = this.state.courses[0].name localStorage.setItem("list", value ); this.setState({courses}); //updates the view };

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回答 1 投票 0




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