原生 js 录屏功能

<!DOCTYPE html>
<html lang="zh-CN">
<head>
	<meta charset="utf-8">
      <title>在线屏幕录制</title>
      <style>
        body{
          font-family: Arial;
          margin: 4vh auto;
          width: 90vw;
          max-width: 600px;
          text-align: center;
        }
        #controls{
          text-align: center;
        }
        .btn{
          margin: 10px 5px;
          padding: 15px;
          background-color: #2bcbba;
          border: none;
          color: white;
          font-weight: bold;
          border-radius: 6px;
          outline: none;
          font-size: 1.2em;
          width: 120px;
          height: 50px;
        }
        .btn:hover{
          background-color: #26de81;
          cursor: hand;
        }
        .btn:disabled{
          background-color: #2bcbba80;
        }
        #stop{
          background-color: #fc5c65;
        }
        #video{
          margin-top: 10px;
          margin-bottom: 20px;
          border: 12px solid #a5adb0 ;
          border-radius: 15px;
          outline: none;
          width: 100%;
          height: 400px;
          background-color: black;
        }
        h1{
          color: #2bcbba;
          letter-spacing:-2.5px;
          line-height: 30px;
        }
        .created{
          color: lightgrey;
          letter-spacing: -0.7px;
          font-size: 1em;
          margin-top: 40px;
        }
        .created > a{
          color: #4b7bec;
          text-decoration: none;
        }
      </style>
    </head>

    <body>
      <h1><u style='color:#fc5c65'>在线屏幕录制</u><br>支持 :新版本 Chrome,Edge,Firefox 桌面浏览器  <br></h1>
      <video autoplay='true' id='video' controls='true' controlsList='nodownload'></video>
      <button class='btn' id='record' onclick='record()'>录制</button>
      <button style='display: none' class='btn' id='stop' onclick='stop()'>停止</button>
      <button disabled='true' class='btn' id='download' onclick='download()'>下载</button>
      <div class='created'>  </div>
    </body>
    <script>
      const video = document.getElementById('video')
      const downloadBtn = document.getElementById('download')
      const recordBtn = document.getElementById('record')
      const stopBtn = document.getElementById('stop')
      let recorder

      async function record() {
		  // 开始录屏
        let captureStream

        try{
          captureStream = await navigator.mediaDevices.getDisplayMedia({
            video: true,
            // audio: true,   not support
            cursor: 'always'
          })
        }catch(e){
			// 取消录屏或者报错
          alert("Could not get stream")
          return
        }

        downloadBtn.disabled = true
        recordBtn.style = 'display: none'
        stopBtn.style = 'display: inline'

		// 删除之前的 Blob
        window.URL.revokeObjectURL(video.src)

        video.autoplay = true

		// 实时的播放录屏
        video.srcObject = captureStream

		// new 一个媒体记录
        recorder = new MediaRecorder(captureStream)
        recorder.start()

        captureStream.getVideoTracks()[0].onended = () => {
			// 录屏结束完成
          recorder.stop()
        }

        recorder.addEventListener("dataavailable", event => {
			// 录屏结束，并且数据可用
			console.log("dataavailable------------")
          let videoUrl = URL.createObjectURL(event.data, {type: 'video/ogg'})

          video.srcObject = null
          video.src = videoUrl
          video.autoplay = false

          downloadBtn.disabled = false
          recordBtn.style = 'display: inline'
          stopBtn.style = 'display: none'
        })
      }

      function download(){
		  // 下载
        const url = video.src
        const name = new Date().toISOString().slice(0, 19).replace('T',' ').replace(" ","_").replace(/:/g,"-")
        const a = document.createElement('a')

        a.style = 'display: none'
        a.download = `${name}.ogg`
        a.href = url

        document.body.appendChild(a)

        a.click()
      }

      function stop(){
        let tracks = video.srcObject.getTracks()
        tracks.forEach(track => track.stop())
        recorder.stop()
      }
    </script>
  </html>