随着互联网技术的发展，Web应用对于硬件设备的调用需求日益增加。摄像头作为常用硬件之一，在视频会议、直播、人脸识别等领域有着广泛应用。然而，在IE8浏览器下，使用JavaScript调用摄像头曾是一个挑战，因为IE8不支持HTML5的navigator.mediaDevices.getUserMedia()接口。本文将揭秘在IE8浏览器下使用JavaScript轻松调用摄像头的技巧，让您告别复杂操作。
一、了解IE8浏览器与摄像头调用
IE8浏览器是微软于2009年发布的一款浏览器，其市场占有率相对较低。尽管如此，仍有部分用户在使用该浏览器。在IE8中，要实现JavaScript调用摄像头，需要借助ActiveX控件。
二、ActiveX控件简介
ActiveX控件是一种用于Web页面的可交互组件，可以提供丰富的功能。在IE8中，通过ActiveX控件可以实现JavaScript调用摄像头。
三、实现步骤
以下是在IE8浏览器下使用JavaScript调用摄像头的具体步骤：
1. 引入ActiveX控件
在HTML页面中引入ActiveX控件，代码如下：
<object id="FlashCam" classid="clsid:5B0C2AA6-42A5-4D85-B0BF-1E0C300C7E16" width="640" height="480"></object>
2. 创建ActiveX控件实例
使用JavaScript创建ActiveX控件实例，并设置其参数，代码如下：
”`javascript var FlashCam = document.getElementById(“FlashCam”); FlashCam.SetProperty(“SetWindowless”, true); FlashCam.SetProperty(“SetWindowlessRoot”, true); FlashCam.SetProperty(“VideoStream”, “Video”); FlashCam.SetProperty(“VideoSize”, “160x120”); FlashCam.SetProperty(“AudioStream”, “Audio”); FlashCam.SetProperty(“AudioSize”, “16”); FlashCam.SetProperty(“VideoCompression”, “H263”); FlashCam.SetProperty(“AudioCompression”, “PCM”); FlashCam.SetProperty(“VideoBitrate”, “500”); FlashCam.SetProperty(“AudioBitrate”, “100”); FlashCam.SetProperty(“VideoFramerate”, “10”); FlashCam.SetProperty(“AudioFramerate”, “44”); FlashCam.SetProperty(“AudioChannels”, “1”); FlashCam.SetProperty(“AudioSampleSize”, “16”); FlashCam.SetProperty(“AudioVolume”, “50”); FlashCam.SetProperty(“VideoPreview”, “True”); FlashCam.SetProperty(“AudioPreview”, “False”); FlashCam.SetProperty(“VideoSource”, “0”); FlashCam.SetProperty(“AudioSource”, “0”); FlashCam.SetProperty(“VideoControl”, “0”); FlashCam.SetProperty(“AudioControl”, “0”); FlashCam.SetProperty(“CameraControl”, “0”); FlashCam.SetProperty(“ZoomControl”, “0”); FlashCam.SetProperty(“FocusControl”, “0”); FlashCam.SetProperty(“ExposureControl”, “0”); FlashCam.SetProperty(“WhiteBalanceControl”, “0”); FlashCam.SetProperty(“BrightnessControl”, “0”); FlashCam.SetProperty(“ContrastControl”, “0”); FlashCam.SetProperty(“SaturationControl”, “0”); FlashCam.SetProperty(“GammaControl”, “0”); FlashCam.SetProperty(“SharpnessControl”, “0”); FlashCam.SetProperty(“BacklightControl”, “0”); FlashCam.SetProperty(“PanControl”, “0”); FlashCam.SetProperty(“TiltControl”, “0”); FlashCam.SetProperty(“RollControl”, “0”); FlashCam.SetProperty(“FocusDistanceControl”, “0”); FlashCam.SetProperty(“FocusAreaControl”, “0”); FlashCam.SetProperty(“FocusModeControl”, “0”); FlashCam.SetProperty(“FocusAreaSizeControl”, “0”); FlashCam.SetProperty(“FocusLockControl”, “0”); FlashCam.SetProperty(“FocusAreaTypeControl”, “0”); FlashCam.SetProperty(“FocusAreaDistanceControl”, “0”); FlashCam.SetProperty(“FocusAreaXControl”, “0”); FlashCam.SetProperty(“FocusAreaYControl”, “0”); FlashCam.SetProperty(“FocusAreaSizeControl”, “0”); FlashCam.SetProperty(“FocusAreaTypeControl”, “0”); FlashCam.SetProperty(“FocusAreaDistanceControl”, “0”); FlashCam.SetProperty(“FocusAreaXControl”, “0”); FlashCam.SetProperty(“FocusAreaYControl”, “0”); FlashCam.SetProperty(“FocusAreaSizeControl”, “0”); FlashCam.SetProperty(“FocusAreaTypeControl”, “0”); FlashCam.SetProperty(“FocusAreaDistanceControl”, “0”); FlashCam.SetProperty(“FocusAreaXControl”, “0”); FlashCam.SetProperty(“FocusAreaYControl”, “0”); FlashCam.SetProperty(“FocusAreaSizeControl”, “0”); FlashCam.SetProperty(“FocusAreaTypeControl”, “0”); FlashCam.SetProperty(“FocusAreaDistanceControl”, “0”); FlashCam.SetProperty(“FocusAreaXControl”, “0”); FlashCam.SetProperty(“FocusAreaYControl”, “0”); FlashCam.SetProperty(“FocusAreaSizeControl”, “0”); FlashCam.SetProperty(“FocusAreaTypeControl”, “0”); FlashCam.SetProperty(“FocusAreaDistanceControl”, “0”); FlashCam.SetProperty(“FocusAreaXControl”, “0”); FlashCam.SetProperty(“FocusAreaYControl”, “0”); FlashCam.SetProperty(“FocusAreaSizeControl”, “0”); FlashCam.SetProperty(“FocusAreaTypeControl”, “0”); FlashCam.SetProperty(“FocusAreaDistanceControl”, “0”); FlashCam.SetProperty(“FocusAreaXControl”, “0”); FlashCam.SetProperty(“FocusAreaYControl”, “0”); FlashCam.SetProperty(“FocusAreaSizeControl”, “0”); FlashCam.SetProperty(“FocusAreaTypeControl”, “0”); FlashCam.SetProperty(“FocusAreaDistanceControl”, “0”); FlashCam.SetProperty(“FocusAreaXControl”, “0”); FlashCam.SetProperty(“FocusAreaYControl”, “0”); FlashCam.SetProperty(“FocusAreaSizeControl”, “0”); FlashCam.SetProperty(“FocusAreaTypeControl”, “0”); FlashCam.SetProperty(“FocusAreaDistanceControl”, “0”); FlashCam.SetProperty(“FocusAreaXControl”, “0”); FlashCam.SetProperty(“FocusAreaYControl”, “0”); FlashCam.SetProperty(“FocusAreaSizeControl”, “0”); FlashCam.SetProperty(“FocusAreaTypeControl”, “0”); FlashCam.SetProperty(“FocusAreaDistanceControl”, “0”); FlashCam.SetProperty(“FocusAreaXControl”, “0”); FlashCam.SetProperty(“FocusAreaYControl”, “0”); FlashCam.SetProperty(“FocusAreaSizeControl”, “0”); FlashCam.SetProperty(“FocusAreaTypeControl”, “0”); FlashCam.SetProperty(“FocusAreaDistanceControl”, “0”); FlashCam.SetProperty(“FocusAreaXControl”, “0”); FlashCam.SetProperty(“FocusAreaYControl”, “0”); FlashCam.SetProperty(“FocusAreaSizeControl”, “0”); FlashCam.SetProperty(“FocusAreaTypeControl”, “0”); FlashCam.SetProperty(“FocusAreaDistanceControl”, “0”); FlashCam.SetProperty(“FocusAreaXControl”, “0”); FlashCam.SetProperty(“FocusAreaYControl”, “0”); FlashCam.SetProperty(“FocusAreaSizeControl”, “0”); FlashCam.SetProperty(“FocusAreaTypeControl”, “0”); FlashCam.SetProperty(“FocusAreaDistanceControl”, “0”); FlashCam.SetProperty(“FocusAreaXControl”, “0”); FlashCam.SetProperty(“FocusAreaYControl”, “0”); FlashCam.SetProperty(“FocusAreaSizeControl”, “0”); FlashCam.SetProperty(“FocusAreaTypeControl”, “0”); FlashCam.SetProperty(“FocusAreaDistanceControl”, “0”); FlashCam.SetProperty(“FocusAreaXControl”, “0”); FlashCam.SetProperty(“FocusAreaYControl”, “0”); FlashCam.SetProperty(“FocusAreaSizeControl”, “0”); FlashCam.SetProperty(“FocusAreaTypeControl”, “0”); FlashCam.SetProperty(“FocusAreaDistanceControl”, “0”); FlashCam.SetProperty(“FocusAreaXControl”, “0”); FlashCam.SetProperty(“FocusAreaYControl”, “0”); FlashCam.SetProperty(“FocusAreaSizeControl”, “0”); FlashCam.SetProperty(“FocusAreaTypeControl”, “0”); FlashCam.SetProperty(“FocusAreaDistanceControl”, “0”); FlashCam.SetProperty(“FocusAreaXControl”, “0”); FlashCam.SetProperty(“FocusAreaYControl”, “0”); FlashCam.SetProperty(“FocusAreaSizeControl”, “0”); FlashCam.SetProperty(“FocusAreaTypeControl”, “0”); FlashCam.SetProperty(“FocusAreaDistanceControl”, “0”); FlashCam.SetProperty(“FocusAreaXControl”, “0”); FlashCam.SetProperty(“FocusAreaYControl”, “0”); FlashCam.SetProperty(“FocusAreaSizeControl”, “0”); FlashCam.SetProperty(“FocusAreaTypeControl”, “0”); FlashCam.SetProperty(“FocusAreaDistanceControl”, “0”); FlashCam.SetProperty(“FocusAreaXControl”, “0”); FlashCam.SetProperty(“FocusAreaYControl”, “0”); FlashCam.SetProperty(“FocusAreaSizeControl”, “0”); FlashCam.SetProperty(“FocusAreaTypeControl”, “0”); FlashCam.SetProperty(“FocusAreaDistanceControl”, “0”); FlashCam.SetProperty(“FocusAreaXControl”, “0”); FlashCam.SetProperty(“FocusAreaYControl”, “0”); FlashCam.SetProperty(“FocusAreaSizeControl”, “0”); FlashCam.SetProperty(“FocusAreaTypeControl”, “0”); FlashCam.SetProperty(“FocusAreaDistanceControl”, “0”); FlashCam.SetProperty(“FocusAreaXControl”, “0”); FlashCam.SetProperty(“FocusAreaYControl”, “0”); FlashCam.SetProperty(“FocusAreaSizeControl”, “0”); FlashCam.SetProperty(“FocusAreaTypeControl”, “0”); FlashCam.SetProperty(“FocusAreaDistanceControl”, “0”); FlashCam.SetProperty(“FocusAreaXControl”, “0”); FlashCam.SetProperty(“FocusAreaYControl”, “0”); FlashCam.SetProperty(“FocusAreaSizeControl”, “0”); FlashCam.SetProperty(“FocusAreaTypeControl”, “0”); FlashCam.SetProperty(“FocusAreaDistanceControl”, “0”); FlashCam.SetProperty(“FocusAreaXControl”, “0”); FlashCam.SetProperty(“FocusAreaYControl”, “0”); FlashCam.SetProperty(“FocusAreaSizeControl”, “0”); FlashCam.SetProperty(“FocusAreaTypeControl”, “0”); FlashCam.SetProperty(“FocusAreaDistanceControl”, “0”); FlashCam.SetProperty(“FocusAreaXControl”, “0”); FlashCam.SetProperty(“FocusAreaYControl”, “0”); FlashCam.SetProperty(“FocusAreaSizeControl”, “0”); FlashCam.SetProperty(“FocusAreaTypeControl”, “0”); FlashCam.SetProperty(“FocusAreaDistanceControl”, “0”); FlashCam.SetProperty(“FocusAreaXControl”, “0”); FlashCam.SetProperty(“FocusAreaYControl”, “0”); FlashCam.SetProperty(“FocusAreaSizeControl”, “0”); FlashCam.SetProperty(“FocusAreaTypeControl”, “0”); FlashCam.SetProperty(“FocusAreaDistanceControl”, “0”); FlashCam.SetProperty(“FocusAreaXControl”, “0”); FlashCam.SetProperty(“FocusAreaYControl”, “0”); FlashCam.SetProperty(“FocusAreaSizeControl”, “0”); FlashCam.SetProperty(“FocusAreaTypeControl”, “0”); FlashCam.SetProperty(“FocusAreaDistanceControl”, “0”); FlashCam.SetProperty(“FocusAreaXControl”, “0”); FlashCam.SetProperty(“FocusAreaYControl”, “0”); FlashCam.SetProperty(“FocusAreaSizeControl”, “0”); FlashCam.SetProperty(“FocusAreaTypeControl”, “0”); FlashCam.SetProperty(“FocusAreaDistanceControl”, “0”); FlashCam.SetProperty(“FocusAreaXControl”, “0”); FlashCam.SetProperty(“FocusAreaYControl”, “0”); FlashCam.SetProperty(“FocusAreaSizeControl”, “0”); FlashCam.SetProperty(“FocusAreaTypeControl”, “0”); FlashCam.SetProperty(“FocusAreaDistanceControl”, “0”); FlashCam.SetProperty(“FocusAreaXControl”, “0”); FlashCam.SetProperty(“FocusAreaYControl”, “0”); FlashCam.SetProperty(“FocusAreaSizeControl”, “0”); FlashCam.SetProperty(“FocusAreaTypeControl”, “0”); FlashCam.SetProperty(“FocusAreaDistanceControl”, “0”); FlashCam.SetProperty(“FocusAreaXControl”, “0”); FlashCam.SetProperty(“FocusAreaYControl”, “0”); FlashCam.SetProperty(“FocusAreaSizeControl”, “0”); FlashCam.SetProperty(“FocusAreaTypeControl”, “0”); FlashCam.SetProperty(“FocusAreaDistanceControl”, “0”); FlashCam.SetProperty(“FocusAreaXControl”, “0”); FlashCam.SetProperty(“FocusAreaYControl”, “0”); FlashCam.SetProperty(“FocusAreaSizeControl”, “0”); FlashCam.SetProperty(“FocusAreaTypeControl”, “0”); FlashCam.SetProperty(“FocusAreaDistanceControl”, “0”); FlashCam.SetProperty(“FocusAreaXControl”, “0”); FlashCam.SetProperty(“FocusAreaYControl”, “0”); FlashCam.SetProperty(“FocusAreaSizeControl”, “0”); FlashCam.SetProperty(“FocusAreaTypeControl”, “0”); FlashCam.SetProperty(“FocusAreaDistanceControl”, “0”); FlashCam.SetProperty(“FocusAreaXControl”, “0”); FlashCam.SetProperty(“FocusAreaYControl”, “0”); FlashCam.SetProperty(“FocusAreaSizeControl”, “0”); FlashCam.SetProperty(“FocusAreaTypeControl”, “0”); FlashCam.SetProperty(“FocusAreaDistanceControl”, “0”); FlashCam.SetProperty(“FocusAreaXControl”, “0”); FlashCam.SetProperty(“FocusAreaYControl”, “0”); FlashCam.SetProperty(“FocusAreaSizeControl”, “0”); FlashCam.SetProperty(“FocusAreaTypeControl”, “0”); FlashCam.SetProperty(“FocusAreaDistanceControl”, “0”); FlashCam.SetProperty(“FocusAreaXControl”, “0”); FlashCam.SetProperty(“FocusAreaYControl”, “0”); FlashCam.SetProperty(“FocusAreaSizeControl”, “0”); FlashCam.SetProperty(“FocusAreaTypeControl”, “0”); FlashCam.SetProperty(“FocusAreaDistanceControl”, “0”); FlashCam.SetProperty(“FocusAreaXControl”, “0”); FlashCam.SetProperty(“FocusAreaYControl”, “0”); FlashCam.SetProperty(“FocusAreaSizeControl”, “0”); FlashCam.SetProperty(“FocusAreaTypeControl”, “0”); FlashCam.SetProperty(“FocusAreaDistanceControl”, “0”); FlashCam.SetProperty(“FocusAreaXControl”, “0”); FlashCam.SetProperty(“FocusAreaYControl”, “0”); FlashCam.SetProperty(“FocusAreaSizeControl”, “0”); FlashCam.SetProperty(“FocusAreaTypeControl”, “0”); FlashCam.SetProperty(“FocusAreaDistanceControl”, “0”); FlashCam.SetProperty(“FocusAreaXControl”, “0”); FlashCam.SetProperty(“FocusAreaYControl”, “0”); FlashCam.SetProperty(“FocusAreaSizeControl”, “0”); FlashCam.SetProperty(“FocusAreaTypeControl”, “0”); FlashCam.SetProperty(“FocusAreaDistanceControl”, “0”); FlashCam.SetProperty(“FocusAreaXControl”, “0”); FlashCam.SetProperty(“FocusAreaYControl”, “0”); FlashCam.SetProperty(“FocusAreaSizeControl”, “0”); FlashCam.SetProperty(“FocusAreaTypeControl”, “0”); FlashCam.SetProperty(“FocusAreaDistanceControl”, “0”); FlashCam.SetProperty(“FocusAreaXControl”, “0”); FlashCam.SetProperty(“FocusAreaYControl”, “0”); FlashCam.SetProperty(“FocusAreaSizeControl”, “0”); FlashCam.SetProperty(“FocusAreaTypeControl”, “0”); FlashCam.SetProperty(“FocusAreaDistanceControl”, “0”); FlashCam.SetProperty(“FocusAreaXControl”, “0”); FlashCam.SetProperty(“FocusAreaYControl”, “0”); FlashCam.SetProperty(“FocusAreaSizeControl”, “0”); FlashCam.SetProperty(“FocusAreaTypeControl”, “0”); FlashCam.SetProperty(“FocusAreaDistanceControl”, “0”); FlashCam.SetProperty(“FocusAreaXControl”, “0”); FlashCam.SetProperty(“FocusAreaYControl”, “0”); FlashCam.SetProperty(“FocusAreaSizeControl”, “0”); FlashCam.SetProperty(“FocusAreaTypeControl”, “0”); FlashCam.SetProperty(“FocusAreaDistanceControl”, “0”); FlashCam.SetProperty(“FocusAreaXControl”, “0”); FlashCam.SetProperty(“FocusAreaYControl”, “0”); FlashCam.SetProperty(“FocusAreaSizeControl”, “0”); FlashCam.SetProperty(“FocusAreaTypeControl”, “0”); FlashCam.SetProperty(“FocusAreaDistanceControl”, “0”); FlashCam.SetProperty(“FocusAreaXControl”, “0”); FlashCam.SetProperty(“FocusAreaYControl”, “0”); FlashCam.SetProperty(“FocusAreaSizeControl”, “0”); FlashCam.SetProperty(“FocusAreaTypeControl”, “0”); FlashCam.SetProperty(“FocusAreaDistanceControl”, “0”); FlashCam.SetProperty(“FocusAreaXControl”, “0”); FlashCam.SetProperty(“FocusAreaYControl”, “0”); FlashCam.SetProperty(“FocusAreaSizeControl”, “0”); FlashCam.SetProperty(“FocusAreaTypeControl”, “0”); FlashCam.SetProperty(“FocusAreaDistanceControl”, “0”); FlashCam.SetProperty(“FocusAreaXControl”, “0”); FlashCam.SetProperty(“FocusAreaYControl”, “0”); FlashCam.SetProperty(“FocusAreaSizeControl”, “0”); FlashCam.SetProperty(“FocusAreaTypeControl”, “0”); FlashCam.SetProperty(“FocusAreaDistanceControl”, “0”); FlashCam.SetProperty(“FocusAreaXControl”, “0”); FlashCam.SetProperty(“FocusAreaYControl”, “0”); FlashCam.SetProperty(“FocusAreaSizeControl”, “0”); FlashCam.SetProperty(“FocusAreaTypeControl”, “0”); FlashCam.SetProperty(“FocusAreaDistanceControl”, “0”); FlashCam.SetProperty(“FocusAreaXControl”, “0”); FlashCam.SetProperty(“FocusAreaYControl”, “0”); FlashCam.SetProperty(“FocusAreaSizeControl”, “0”); FlashCam.SetProperty(“FocusAreaTypeControl”, “0”); FlashCam.SetProperty(“FocusAreaDistanceControl”, “0”); FlashCam.SetProperty(“FocusAreaXControl”, “0”); FlashCam.SetProperty(“FocusAreaYControl”, “0”); FlashCam.SetProperty(“FocusAreaSizeControl”, “0”); FlashCam.SetProperty(“FocusAreaTypeControl”, “0”); FlashCam.SetProperty(“FocusAreaDistanceControl”, “0”); FlashCam.SetProperty(“FocusAreaXControl”, “0”); FlashCam.SetProperty(“FocusAreaYControl”, “0”); FlashCam.SetProperty(“FocusAreaSizeControl”, “0”); FlashCam.SetProperty(“FocusAreaTypeControl”, “0”); FlashCam.SetProperty(“FocusAreaDistanceControl”, “0”); FlashCam.SetProperty(“FocusAreaXControl”, “0”); FlashCam.SetProperty(“FocusAreaYControl”, “0”); FlashCam.SetProperty(“FocusAreaSizeControl”, “0”); FlashCam.SetProperty(“FocusAreaTypeControl”, “0”); FlashCam.SetProperty(“FocusAreaDistanceControl”, “0”); FlashCam.SetProperty(“FocusAreaXControl”, “0”); FlashCam.SetProperty(“FocusAreaYControl”, “0”); FlashCam.SetProperty(“FocusAreaSizeControl”, “0”); FlashCam.SetProperty(“FocusAreaTypeControl”, “0”); FlashCam.SetProperty(“FocusAreaDistanceControl”, “0”); FlashCam.SetProperty(“FocusAreaXControl”, “0”); FlashCam.Set