临时的录屏工具

不需要下载任何 APP，用一段 JS 代码就可以实现了。

    const  startRecord = async function () {
        var stream = await navigator.mediaDevices.getDisplayMedia({ video: true });
        var mime = MediaRecorder.isTypeSupported("video/mp4; codecs=vp9") ? "video/mp4; codecs=vp9" : "video/mp4";
        var mediaRecorder = new MediaRecorder(stream, { mimeType: mime });
        //录制
        var chunks = [];
        mediaRecorder.addEventListener("dataavailable", function (e) {
            chunks.push(e.data);
        });
        //停止
        mediaRecorder.addEventListener("stop", function () {
            var blob = new Blob(chunks, { type: chunks[0].type });
            var url = URL.createObjectURL(blob);
            var a = document.createElement("a");
            a.href = url;
            let name = prompt("输入保存名称","视频录制"+new Date().toLocaleDateString()+" "+new Date().toLocaleTimeString())
            a.download = name+".mp4";
            a.click();
            
        });
        //手动启动
        mediaRecorder.start();
};