用C#如何控制两个摄像头显示？

如题，一个摄像头好控制，但两个摄像头不知道怎么办，请高手帮忙，下面是控制一个摄像头的代码：using System;
using System.Collections.Generic;
using System.Text;
using System.Drawing;
using System.Runtime.InteropServices.ComTypes;
using System.Windows.Forms;
using System.Runtime.InteropServices;namespace WindowsApplication1
{
    public class Video
    {
        const short WM_CAP = 1024;
        const int WM_CAP_DRIVER_CONNECT = WM_CAP + 10;
        const int WM_CAP_DRIVER_DISCONNECT = WM_CAP + 11;
        const int WM_CAP_EDIT_COPY = WM_CAP + 30;
        const int WM_CAP_SET_PREVIEW = WM_CAP + 50;
        const int WM_CAP_SET_PREVIEWRATE = WM_CAP + 52;
        const int WM_CAP_SET_SCALE = WM_CAP + 53;
        const int WS_CHILD = 1073741824;
        const int WS_VISIBLE = 268435456;
        const short SWP_NOMOVE = 2;
        const short SWP_NOSIZE = 1;
        const short SWP_NOZORDER = 4;
        const short HWND_BOTTOM = 1;
        int iDevice = 0;
        int iHandle;
        int hHwnd;
        short iWidth = 640;
        short iHeight = 480;
        [System.Runtime.InteropServices.DllImport("user32", EntryPoint = "SendMessageA")]
        static extern int SendMessage(int hwnd, int wMsg, int wParam, [MarshalAs(UnmanagedType.AsAny)] 
            object lParam);
        [System.Runtime.InteropServices.DllImport("user32", EntryPoint = "SetWindowPos")]
        static extern int SetWindowPos(int hwnd, int hWndInsertAfter, int x, int y, int cx, int cy, int wFlags);
        [System.Runtime.InteropServices.DllImport("user32")]
        static extern bool DestroyWindow(int hndw);
        [System.Runtime.InteropServices.DllImport("avicap32.dll")]
        static extern int capCreateCaptureWindowA(string lpszWindowName, int dwStyle, int x, int y, int nWidth, short nHeight, int hWndParent, int nID);
        [System.Runtime.InteropServices.DllImport("avicap32.dll")]
        static extern bool capGetDriverDescriptionA(short wDriver, string lpszName, int cbName, string lpszVer, int cbVer);        public Video(int handleId, int deviceId, short width, short height)
        {
            iHandle = handleId;
            iDevice = deviceId;
            iWidth = width;
            iHeight = height;
        }        public  void OpenPreviewWindow()
        {
            hHwnd = capCreateCaptureWindowA(iDevice.ToString(), (WS_VISIBLE | WS_CHILD), 0, 0, iWidth, iHeight, iHandle, 0);            if (SendMessage(hHwnd, WM_CAP_DRIVER_CONNECT, iDevice, 0) == 1)
            {
                SendMessage(hHwnd, WM_CAP_SET_SCALE, 1, 0);
                SendMessage(hHwnd, WM_CAP_SET_PREVIEWRATE, 66, 0);
                SendMessage(hHwnd, WM_CAP_SET_PREVIEW, 1, 0);
                SetWindowPos(hHwnd, HWND_BOTTOM, 0, 0, iWidth, iHeight, (SWP_NOMOVE | SWP_NOZORDER));
            }
            else
            {
                DestroyWindow(hHwnd);
            }
        }        public  void ClosePreviewWindow()
        {
            SendMessage(hHwnd, WM_CAP_DRIVER_DISCONNECT, iDevice, 0);
            DestroyWindow(hHwnd);
        }        public Image CutVideo()
        {
            System.Windows.Forms.IDataObject data;
            Image bmap = null;            //  Copy image to clipboard
            SendMessage(hHwnd, WM_CAP_EDIT_COPY, 0, 0);            //  Get image from clipboard and convert it to a bitmap
            data = Clipboard.GetDataObject();            if (data.GetDataPresent(typeof(System.Drawing.Bitmap)))
            {
                bmap = ((Image)(data.GetData(typeof(System.Drawing.Bitmap))));
            }            return bmap;
        }
    }
}