C#制作ActiveX控件中调用海康SDK的问题

using System;
using System.Windows.Forms;
using System.IO;
using System.Runtime.InteropServices;
namespace VideoHelper
{
    [System.Security.SecuritySafeCritical]
    [Guid("79629620-3C0C-4D47-B93B-2D36AEF8EF31")]
    public partial class VideoControl : UserControl,IObjectSafety
    {
        public VideoControl()
        {
            InitializeComponent();
        }
        string videopath = Environment.CurrentDirectory;
        Videos video;
        IntPtr handle;
        private void btnLogin_Click(object sender, EventArgs e)
        {
            if (btnLogin.Text == "登录")
            {
                try
                {
                    if (string.IsNullOrWhiteSpace(this.txtIP.Text))
                    {
                        MessageBox.Show("IP地址不能为空！");
                        return;
                    }
                    if (string.IsNullOrWhiteSpace(this.txtUserID.Text))
                    {
                        MessageBox.Show("用户名不能为空！");
                        return;
                    }
                    if (string.IsNullOrWhiteSpace(this.txtPwd.Text))
                    {
                        MessageBox.Show("密码不能为空！");
                        return;
                    }
                    video = new Videos();
                    if (video.Initialize(this.txtIP.Text, Convert.ToInt32(this.numericUpDown1.Value), this.txtUserID.Text, this.txtPwd.Text))
                    {
                        this.btnLogin.Text = "注销";
                        MessageBox.Show("登录成功！");
                        this.btnStart.Enabled = true;
                        this.btnSave.Enabled = true;
                    }
                    else
                    {
                        MessageBox.Show("登录失败！");
                    }
                }
                catch (Exception ee)
                {
                    MessageBox.Show("登录异常：" + ee.Message);
                }
            }
            else if (btnLogin.Text == "注销")
            {
                try
                {
                    video.Dispose();
                    this.btnLogin.Text = "登录";
                    this.btnStart.Enabled = false;
                    this.btnSave.Enabled = false;
                }
                catch (Exception ee)
                {
                    MessageBox.Show("注销异常：" + ee.Message);
                }
            }
        }

        private void btnStart_Click(object sender, EventArgs e)
        {
            try
            {
                string filename = txtFile.Text.Trim();
                if (filename.IndexOfAny(Path.GetInvalidFileNameChars()) >= 0 || string.IsNullOrWhiteSpace(filename))
                {
                    MessageBox.Show("文件名含有非法字符或空格，请重新输入");
                    txtFile.Focus();
                    return;
                }
                video.Start(handle, filename + comboBox1.SelectedItem.ToString());
                this.btnStart.Enabled = false;
                this.btnSave.Enabled = true;
            }
            catch (Exception ee)
            {
                MessageBox.Show("异常：" + ee.Message);
            }
        }

        private void btnSave_Click(object sender, EventArgs e)
        {
            try
            {
                if (video.End())
                {
                    MessageBox.Show("视频已保存！");
                    this.btnStart.Enabled = true;
                    this.btnSave.Enabled = false;
                }
                else
                {
                    MessageBox.Show("保存失败！");
                    this.btnStart.Enabled = true;
                    this.btnSave.Enabled = true;
                }
            }
            catch (Exception ee)
            { MessageBox.Show("异常：" + ee.Message); }
        }

        private void button1_Click(object sender, EventArgs e)
        {
            try
            {
                System.Diagnostics.Process.Start(videopath);

            }
            catch
            { }
        }

        private void VideoControl_Load(object sender, EventArgs e)
        {
            this.comboBox1.SelectedItem = ".mp4";
            this.handle = pictureBox1.Handle;
            this.btnStart.Enabled = false;
            this.btnSave.Enabled = false;
        }

        #region IObjectSafety 成员
        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
    }
}