C# Activex调用USB摄像头--附带源码

 /*
      iobjectsafety 接口用于通知浏览器：“浏览器，我是安全的”
     */
    [comimport, guid("887fc3c3-a970-4a36-92ef-d4eb31541c40")]
    [interfacetypeattribute(cominterfacetype.interfaceisiunknown)]
    public interface iobjectsafety
    {
        [preservesig]
        int getinterfacesafetyoptions(ref guid riid, [marshalas(unmanagedtype.u4)] ref int pdwsupportedoptions, [marshalas(unmanagedtype.u4)] ref int pdwenabledoptions);

        [preservesig()]
        int setinterfacesafetyoptions(ref guid riid, [marshalas(unmanagedtype.u4)] int dwoptionsetmask, [marshalas(unmanagedtype.u4)] int dwenabledoptions);
    }

 public class usbinfo
    {
        /// <summary>
        /// 返回消息
        /// </summary>
        public class returnmessage
        {
            public bool result { get; set; }//结果
            public string message { get; set; }//消息
        }

        /// <summary>
        /// 返回视频分辨率
        /// </summary>
        public class getresolvingpower
        {
            public int index { get; set; }//下标 -1（不存在摄像头），-2（发生意外错误）
            public videocapabilities capabilities { get; set; }//信息
            public string error { get; set; }//错误
        }

    }

 /// <summary>
    /// 继承iobjectsafety
    /// </summary>
    [progid("usbcamera")]
    [classinterface(classinterfacetype.autodual)]
    [guid("887fc3c3-a970-4a36-92ef-d4eb31541c40")]
    [comvisible(true)]
    public partial class usbcamera : usercontrol, iobjectsafety
    {
        filterinfocollection videodevices;//设备
        videocapturedevice videosource;//设备信息
        memorystream framedata;//图片数据
        static thread th_usb;//监听线程
        static int sl_usb = 10000;//多久检查一次
        static int index_usb;//第一次打开选择的分辨率

        public usbcamera()
        {
            initializecomponent();
            framedata = new memorystream();
        }

        //句柄销毁
        protected override void onhandledestroyed(eventargs e)
        {
            stop();
            base.onhandledestroyed(e);
        }

        /// <summary>
        /// 设置窗体相关大小
        /// </summary>
        /// <param name="width">宽</param>
        /// <param name="height">高</param>
        /// <param name="fontformat">字体熟悉</param>
        /// <param name="fontsize">字体大小</param>
        /// <param name="promptinfo">提示信息</param>
        /// <param name="sleep">监听间隔</param>
        public void formsize(int width, int height, string fontformat, int fontsize, string promptinfo, int sleep)
        {
            this.size = new size(width, height);//窗体大小
            this.lab_prompt.font = new font(fontformat, fontsize, fontstyle.bold); //字体熟悉
            this.lab_prompt.forecolor = color.red;//字体颜色
            this.lab_prompt.text = promptinfo;//提示信息

            //设置字体高宽
            var lab_width = (width / 3);
            var lab_height = (height / 3);
            this.lab_prompt.location = new system.drawing.point(lab_width, lab_height);
            sl_usb = sleep;//监听时间
        }

        /// <summary>
        /// 打开视频
        /// </summary>
        /// <param name="index">usb可用分辨率数组下标</param>
        public void start(int index)
        {
            index_usb = index;
            if (videosource != null)
            {
                videosource.newframe -= new newframeeventhandler(video_newframe);
                videosource.signaltostop();
                videosource = null;
            }
            // 创建视频源
            trace.writeline("usbcamera have cameras" + videodevices.count.tostring());
            videosource = new videocapturedevice(videodevices[0].monikerstring);
            // 设置新帧事件处理程序
            videosource.newframe += new newframeeventhandler(video_newframe);
            // 启动视频源
            try
            {
                videosource.videoresolution = this.videosource.videocapabilities[index];
                videosource.start();

                if (th_usb == null || !th_usb.isalive)
                {
                    th_usb = new thread(getusb);
                    th_usb.start();
                }
                this.lab_prompt.text = null;
            }
            catch (exception ex)
            {
                trace.writeline("usbcamera start()遇到错误" + ex.message + ex.stacktrace);
            }
        }

        /// <summary>
        /// 停止视频
        /// </summary>
        public void stop()
        {
            if (videosource != null)
            {
                videosource.newframe -= new newframeeventhandler(video_newframe);
                //当不再需要捕捉时，发出停止的信号
                videosource.signaltostop();
                videosource = null;
                trace.writeline("usbcamera stop()....");
                if (picturebox1.image != null)//清空控件
                {
                    picturebox1.image.dispose();
                    picturebox1.image = null;
                }
                this.lab_prompt.text = null;
            }
        }

        /// <summary>
        /// 视频帧获取回调
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="eventargs"></param>
        private void video_newframe(object sender, newframeeventargs eventargs)
        {
            try
            {
                lab_prompt.text = null;
                trace.writeline("usbcamera video_newframe()....");
                eventargs.frame.save(framedata, imageformat.bmp);
                if (picturebox1.invokerequired)
                {
                    //写入数据
                    picturebox1.begininvoke((methodinvoker)delegate ()
                    {
                        try
                        {
                            if (picturebox1.image != null)
                            {
                                image img = picturebox1.image;
                                img.dispose();
                            }
                            picturebox1.image = new bitmap(framedata);
                        }
                        catch (exception ex)
                        {
                            if (picturebox1.image != null)
                            {
                                picturebox1.image.dispose();
                                picturebox1.image = null;
                            }
                        }
                    });
                }
                else
                {
                    picturebox1.image = new bitmap(framedata);
                }
            }
            catch (exception ex)
            {
                if (picturebox1.image != null)
                {
                    picturebox1.image.dispose();
                    picturebox1.image = null;
                }
            }
        }

        /// <summary>
        /// 获取usb（usb连接不正常），不存在给出提示，存在重新start
        /// </summary>
        public void getusb()
        {
            while (true)
            {
                var usb = new filterinfocollection(filtercategory.videoinputdevice);
                if (usb.count <= 0)
                {
                    stop();
                    lab_prompt.begininvoke((methodinvoker)delegate ()
                    {
                        this.lab_prompt.text = "未连接上摄像头，检查连接是否正常。";
                    });
                }
                else
                {
                    //重新连接上 执行start
                    if (!string.isnullorwhitespace(this.lab_prompt.text))
                    {
                        start(index_usb);
                    }
                }
                thread.sleep(sl_usb);
            }
        }

        #region usb视频操作
        /// <summary>
        /// 测试activex是否可用
        /// </summary>
        /// <returns>true/false</returns>
        public bool connection()
        {
            return true;
        }

        /// <summary>
        /// 获取截图
        /// </summary>
        /// <returns></returns>
        public returnmessage getscreenshots()
        {
            try
            {
                return new returnmessage()
                {
                    result = true,
                    message = convert.tobase64string(framedata.toarray())
                };
            }
            catch (exception ex)
            {
                trace.writeline("usbcamera getimage() 错误...." + ex.message + ex.stacktrace);
                return new returnmessage() { result = false, message = ex.message + " " + ex.stacktrace };
            }
        }

        /// <summary>
        /// 获取usb摄像头分辨率
        /// </summary>
        /// <returns>json(getresolvingpower)</returns>
        public string getresolution()
        {
            var list = new list<getresolvingpower>();
            try
            {
                videodevices = new filterinfocollection(filtercategory.videoinputdevice);
                if (videodevices.count > 0)
                {
                    videosource = new videocapturedevice(videodevices[0].monikerstring);
                    for (int i = 0; i < videosource.videocapabilities.length; i++)
                    {
                        list.add(new getresolvingpower
                        {
                            index = i,
                            capabilities = videosource.videocapabilities[i],
                        });
                    }
                }
                else
                {
                    list.add(new getresolvingpower
                    {
                        index = -1,
                        capabilities = null,
                        error = "不存在usb摄像头",
                    });
                }
            }
            catch (exception ex)
            {
                list.add(new getresolvingpower
                {
                    index = -2,
                    capabilities = null,
                    error = ex.source + " " + ex.message
                });
            }
            return newtonsoft.json.jsonconvert.serializeobject(list);
        }
        #endregion

        #region iobjectsafety 成员直接复制
        private const string _iid_idispatch = "{00020400-0000-0000-c000-000000000046}";
        private const string _iid_idispatchex = "{a6ef9860-c720-11d0-9337-00a0c90dcaa9}";
        private const string _iid_ipersiststorage = "{0000010a-0000-0000-c000-000000000046}";
        private const string _iid_ipersiststream = "{00000109-0000-0000-c000-000000000046}";
        private const string _iid_ipersistpropertybag = "{37d84f60-42cb-11ce-8135-00aa004bb851}";

        private const int interfacesafe_for_untrusted_caller = 0x00000001;
        private const int interfacesafe_for_untrusted_data = 0x00000002;
        private const int s_ok = 0;
        private const int e_fail = unchecked((int)0x80004005);
        private const int e_nointerface = unchecked((int)0x80004002);

        private bool _fsafeforscripting = true;
        private bool _fsafeforinitializing = true;

        public int getinterfacesafetyoptions(ref guid riid, ref int pdwsupportedoptions, ref int pdwenabledoptions)
        {
            int rslt = e_fail;

            string strguid = riid.tostring("b");
            pdwsupportedoptions = interfacesafe_for_untrusted_caller | interfacesafe_for_untrusted_data;
            switch (strguid)
            {
                case _iid_idispatch:
                case _iid_idispatchex:
                    rslt = s_ok;
                    pdwenabledoptions = 0;
                    if (_fsafeforscripting == true)
                        pdwenabledoptions = interfacesafe_for_untrusted_caller;
                    break;
                case _iid_ipersiststorage:
                case _iid_ipersiststream:
                case _iid_ipersistpropertybag:
                    rslt = s_ok;
                    pdwenabledoptions = 0;
                    if (_fsafeforinitializing == true)
                        pdwenabledoptions = interfacesafe_for_untrusted_data;
                    break;
                default:
                    rslt = e_nointerface;
                    break;
            }

            return rslt;
        }

        public int setinterfacesafetyoptions(ref guid riid, int dwoptionsetmask, int dwenabledoptions)
        {
            int rslt = e_fail;
            string strguid = riid.tostring("b");
            switch (strguid)
            {
                case _iid_idispatch:
                case _iid_idispatchex:
                    if (((dwenabledoptions & dwoptionsetmask) == interfacesafe_for_untrusted_caller) && (_fsafeforscripting == true))
                        rslt = s_ok;
                    break;
                case _iid_ipersiststorage:
                case _iid_ipersiststream:
                case _iid_ipersistpropertybag:
                    if (((dwenabledoptions & dwoptionsetmask) == interfacesafe_for_untrusted_data) && (_fsafeforinitializing == true))
                        rslt = s_ok;
                    break;
                default:
                    rslt = e_nointerface;
                    break;
            }

            return rslt;
        }

        #endregion
    }

<!doctype html>
<html>
<head>
    <meta http-equiv="content-type" content="text/html; charset=utf-8" />
    <title></title>
    <meta charset="utf-8" />
    <script>

        //初始化 设置usb控件大小和显示
        var array = new array();
        window.onload = function () {
            var usbcamera = document.getelementbyid("usbcamera");
            usbcamera.stop(); //停止视频
            array = json.parse(document.getelementbyid("usbcamera").getresolution());//获取usb分辨率

            /*
            判断获取数据是否成功（usb连接是否正常）
            大于1为成功，摄像头基本有多个分辨率
            也可以判断返回值中index是否为负数
            获取到的分辨率最大的为第一个下标为：0
            */
            if (array.length > 1) {
                //分辨率下标 宽 高
                var index = 0, width = 0, height = 0;
                for (var i = 0; i < array.length; i++) {
                    var size = array[i].capabilities.framesize;
                    if (size.width > width && size.height > height) {
                        index = i;
                        width = size.width;
                        height = size.height;
                    }
                }
                //此处我获取分辨率的最大值赋值，实际可以更改
                usbcamera.formsize(width, height, "宋体", 9, "", 10000);//初始化
                usbcamera.start(index);//打开摄像头
            } else {
                if (array[0].index == -1) { //-1未连接
                    usbcamera.fromsize(400, 400, "宋体", 9, "摄像头未连接", 10000);

                } if (array[0].index == -2) { //-2 获取是发生错误
                    usbcamera.fromsize(400, 400, "宋体", 9, "摄像头连接有异常，请联系管理人员！", 10000);
                }
            }
        }

        //关闭时执行stop
        window.beforeunloadevent = function () {
            document.getelementbyid("usbcamera").stop();
        }

        //测试连接
        function testconnection() {
            alert(document.getelementbyid("usbcamera").connection());
        }

        //打开摄像头
        function startcamera() {
            document.getelementbyid("usbcamera").start(0);
        }

        //关闭摄像头
        function stopcamera() {
            document.getelementbyid("usbcamera").stop();
        }

        //获取截图
        function getscreenshots() {
            var imginfo = document.getelementbyid("usbcamera").getscreenshots();
            if (imginfo.result) {
                document.getelementbyid("displayscreenshots").src = "data:image/jpg;base64," + imginfo.message;
            } else {
                alert("截图获取失败");
            }
        }

        //获取分辨率
        function getresolution() {
            console.log(document.getelementbyid("usbcamera").getresolution());
        }
    </script>

</head>
<body>
    <div>
        <button onclick="testconnection()">测试连接</button>
        <button onclick="startcamera()">打开摄像头</button>
        <button onclick="stopcamera()">关闭摄像头</button>
        <button onclick="getscreenshots()">获取截图</button>
        <button onclick="getresolution()">获取分辨率</button>
    </div>
    <hr />
    <h3>截图显示</h3>
    <img style="width:300px;height:300px;" id="displayscreenshots" />
    <div style="float:right;width:70%">
        <object id="usbcamera" classid="clsid:887fc3c3-a970-4a36-92ef-d4eb31541c40">
            <div class="alert alert-danger">视频控件载入失败！如未安装，请<a href="installationpackage/setup1.msi">下载安装</a>。</div>
        </object>
    </div>
</body>
</html>