C#打开电脑摄像头

【实例截图】

【核心代码】

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Runtime.InteropServices;

namespace 打开摄像头
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {

        }
        /// <summary>
        /// Form1 handle. 
        /// </summary>
        private int hHwnd;

        public struct videohdr_tag
        {
            public byte[] lpData;
            public int dwBufferLength;
            public int dwBytesUsed;
            public int dwTimeCaptured;
            public int dwUser;
            public int dwFlags;
            public int[] dwReserved;
        }

        #region P/Invoke

        [DllImport("avicap32.dll", CharSet = CharSet.Ansi, SetLastError = true, ExactSpelling = true)]
        public static extern int capCreateCaptureWindowA([MarshalAs(UnmanagedType.VBByRefStr)]   ref string lpszWindowName, int dwStyle, int x, int y, int nWidth, short nHeight, int hWndParent, int nID);
        [DllImport("avicap32.dll", CharSet = CharSet.Ansi, SetLastError = true, ExactSpelling = true)]
        public static extern bool capGetDriverDescriptionA(short wDriver, [MarshalAs(UnmanagedType.VBByRefStr)]   ref string lpszName, int cbName, [MarshalAs(UnmanagedType.VBByRefStr)]   ref string lpszVer, int cbVer);
        [DllImport("user32", CharSet = CharSet.Ansi, SetLastError = true, ExactSpelling = true)]
        public static extern bool DestroyWindow(int hndw);
        [DllImport("user32", EntryPoint = "SendMessageA", CharSet = CharSet.Ansi, SetLastError = true, ExactSpelling = true)]
        public static extern int SendMessage(int hwnd, int wMsg, int wParam, [MarshalAs(UnmanagedType.AsAny)]   object lParam);
        [DllImport("user32", CharSet = CharSet.Ansi, SetLastError = true, ExactSpelling = true)]
        public static extern int SetWindowPos(int hwnd, int hWndInsertAfter, int x, int y, int cx, int cy, int wFlags);
        [DllImport("vfw32.dll")]
        public static extern string capVideoStreamCallback(int hwnd, videohdr_tag videohdr_tag);
        [DllImport("vicap32.dll", CharSet = CharSet.Ansi, SetLastError = true, ExactSpelling = true)]
        public static extern bool capSetCallbackOnFrame(int hwnd, string s);

        #endregion

        #region 初始化窗体1并在面板中显示视频
        /// <summary>
        /// Initialize Form1 and display the video in a panel.
        /// 初始化窗体1并在面板中显示视频
        /// display  展示  显示
        /// </summary>
        /// <returns></returns>
        private bool InitializeForm1()  //初始化 计算机程序或者系统
        {
            bool ok = false;

            int intWidth = this.pictureBox1.Width;
            int intHeight = this.pictureBox1.Height;
            int intDevice = 0;
            string refDevice = intDevice.ToString();

            //Create vedio and get the window handle.
            hHwnd = Form1.capCreateCaptureWindowA(ref refDevice, 1342177280, 0, 0, 640, 480, this.pictureBox1.Handle.ToInt32(), 0);

            if (Form1.SendMessage(hHwnd, 0x40a, intDevice, 0) > 0)
            {
                Form1.SendMessage(this.hHwnd, 0x435, -1, 0);
                Form1.SendMessage(this.hHwnd, 0x434, 0x42, 0);
                Form1.SendMessage(this.hHwnd, 0x432, -1, 0);
                Form1.SetWindowPos(this.hHwnd, 1, 0, 0, intWidth, intHeight, 6);

                ok = true;
            }
            else
            {
                Form1.DestroyWindow(this.hHwnd);
            }

            return ok;
        }
        #endregion
        #region 应用程序运行，然后调用Form1直到成功
        /// <summary>
        /// App run, then invoke the Form1 till successfully.
        /// 应用程序运行，然后调用Form1直到成功
        /// till 直到
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>

        private void CloseForm1()
        {
            if (this.hHwnd > 0)
            {
                Form1.SendMessage(this.hHwnd, 0x40b, 0, 0);
                Form1.DestroyWindow(this.hHwnd);
            }
        }
        #endregion
        #region 关闭窗口时，销毁窗体1窗口
        /// <summary>
        /// when close window, destroy the Form1 window.
        /// 关闭窗口时，销毁窗体1窗口
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void Form1_FormClosed(object sender, FormClosedEventArgs e)
        {
            CloseForm1();
        }
        #endregion
        #region 当窗口大小改变时，调整窗体1图片的大小
        /// <summary>
        /// when window size changed, resize Form1 pic.
        /// 当窗口大小改变时，调整窗体1图片的大小。
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void Form1_SizeChanged(object sender, EventArgs e)
        {
            Form1.SetWindowPos(this.hHwnd, 1, 0, 0, this.Width, this.Height, 6);
        }

        #endregion

        private void but_打开摄像头_Click(object sender, EventArgs e)
        {
            bool ok = false;

            while (!ok)
            {
                ok = this.InitializeForm1();
                System.Threading.Thread.Sleep(10);
            }
        }

        private void but_关闭摄像头_Click(object sender, EventArgs e)
        {

            CloseForm1();

        }
    }

}