摄像头编程 选择自 libiegoupan 的 Blog

导读：
　　这是一个关于设想头的类
　　using System;
　　using System.Runtime.InteropServices;
　　namespace webcam
　　{
　　///
　　/// avicap 的摘要说明。
　　///
　　public class showVideo
　　{
　　// showVideo calls
　　[DllImport("avicap32.dll")] public static extern IntPtr capCreateCaptureWindowA(byte[] lpszWindowName, int dwStyle, int x, int y, int nWidth, int nHeight, IntPtr hWndParent, int nID);
　　[DllImport("avicap32.dll")] public static extern bool capGetDriverDescriptionA(short wDriver, byte[] lpszName, int cbName, byte[] lpszVer, int cbVer);
　　[DllImport("User32.dll")] public static extern bool SendMessage(IntPtr hWnd, int wMsg, bool wParam, int lParam);
　　[DllImport("User32.dll")] public static extern bool SendMessage(IntPtr hWnd, int wMsg, short wParam, int lParam);
　　[DllImport("User32.dll")] public static extern bool SendMessage(IntPtr hWnd, int wMsg, short wParam, FrameEventHandler lParam);
　　[DllImport("User32.dll")] public static extern bool SendMessage(IntPtr hWnd, int wMsg, int wParam, ref BITMAPINFO lParam);
　　[DllImport("User32.dll")] public static extern int SetWindowPos(IntPtr hWnd, int hWndInsertAfter, int x, int y, int cx, int cy, int wFlags);
　　[DllImport("avicap32.dll")]public static extern int capGetVideoFormat(IntPtr hWnd, IntPtr psVideoFormat, int wSize );
　　// Constants
　　public const int WM_USER = 0x400;
　　public const int WS_CHILD = 0x40000000;
　　public const int WS_VISIBLE = 0x10000000;
　　public const int SWP_NOMOVE = 0x2;
　　public const int SWP_NOZORDER = 0x4;
　　public const int WM_CAP_DRIVER_CONNECT = WM_USER + 10;
　　public const int WM_CAP_DRIVER_DISCONNECT = WM_USER + 11;
　　public const int WM_CAP_SET_CALLBACK_FRAME = WM_USER + 5;
　　public const int WM_CAP_SET_PREVIEW = WM_USER + 50;
　　public const int WM_CAP_SET_PREVIEWRATE = WM_USER + 52;
　　public const int WM_CAP_SET_VIDEOFORMAT = WM_USER + 45;
　　
　　// Structures
　　[StructLayout(LayoutKind.Sequential)] public struct VIDEOHDR
　　{
　　[MarshalAs(UnmanagedType.I4)] public int lpData;
　　[MarshalAs(UnmanagedType.I4)] public int dwBufferLength;
　　[MarshalAs(UnmanagedType.I4)] public int dwBytesUsed;
　　[MarshalAs(UnmanagedType.I4)] public int dwTimeCaptured;
　　[MarshalAs(UnmanagedType.I4)] public int dwUser;
　　[MarshalAs(UnmanagedType.I4)] public int dwFlags;
　　[MarshalAs(UnmanagedType.ByValArray, SizeConst=4)] public int[] dwReserved;
　　}
　　[StructLayout(LayoutKind.Sequential)] public struct BITMAPINFOHEADER
　　{
　　[MarshalAs(UnmanagedType.I4)] public Int32 biSize ;
　　[MarshalAs(UnmanagedType.I4)] public Int32 biWidth ;
　　[MarshalAs(UnmanagedType.I4)] public Int32 biHeight ;
　　[MarshalAs(UnmanagedType.I2)] public short biPlanes;
　　[MarshalAs(UnmanagedType.I2)] public short biBitCount ;
　　[MarshalAs(UnmanagedType.I4)] public Int32 biCompression;
　　[MarshalAs(UnmanagedType.I4)] public Int32 biSizeImage;
　　[MarshalAs(UnmanagedType.I4)] public Int32 biXPelsPerMeter;
　　[MarshalAs(UnmanagedType.I4)] public Int32 biYPelsPerMeter;
　　[MarshalAs(UnmanagedType.I4)] public Int32 biClrUsed;
　　[MarshalAs(UnmanagedType.I4)] public Int32 biClrImportant;
　　}
　　[StructLayout(LayoutKind.Sequential)] public struct BITMAPINFO
　　{
　　[MarshalAs(UnmanagedType.Struct, SizeConst=40)] public BITMAPINFOHEADER bmiHeader;
　　[MarshalAs(UnmanagedType.ByValArray, SizeConst=1024)] public Int32[] bmiColors;
　　}
　　
　　public delegate void FrameEventHandler(IntPtr lwnd, IntPtr lpVHdr);
　　
　　// Public methods
　　public static object GetStructure(IntPtr ptr,ValueType structure)
　　{
　　return Marshal.PtrToStructure(ptr,structure.GetType());
　　}
　　
　　public static object GetStructure(int ptr,ValueType structure)
　　{
　　return GetStructure(new IntPtr(ptr),structure);
　　}
　　
　　public static void Copy(IntPtr ptr,byte[] data)
　　{
　　Marshal.Copy(ptr,data,0,data.Length);
　　}
　　
　　public static void Copy(int ptr,byte[] data)
　　{
　　Copy(new IntPtr(ptr),data);
　　}
　　
　　public static int SizeOf(object structure)
　　{
　　return Marshal.SizeOf(structure);
　　}
　　}
　　//Web Camera Class
　　public class WebCamera
　　{
　　// Constructur
　　public WebCamera(IntPtr handle, int width,int height)
　　{
　　mControlPtr = handle;
　　mWidth = width;
　　mHeight = height;
　　}
　　
　　// delegate for frame callback
　　public delegate void RecievedFrameEventHandler(byte[] data);
　　public event RecievedFrameEventHandler RecievedFrame;
　　
　　private IntPtr lwndC; // Holds the unmanaged handle of the control
　　private IntPtr mControlPtr; // Holds the managed pointer of the control
　　private int mWidth;
　　private int mHeight;
　　
　　private showVideo.FrameEventHandler mFrameEventHandler; // Delegate instance for the frame callback - must keep alive! gc should NOT collect it
　　
　　// Close the web camera
　　public void CloseWebcam()
　　{
　　this.capDriverDisconnect(this.lwndC);
　　}
　　
　　// start the web camera
　　public void StartWebCam()
　　{
　　byte[] lpszName = new byte[100];
　　byte[] lpszVer = new byte[100];
　　
　　showVideo.capGetDriverDescriptionA(0, lpszName, 100,lpszVer, 100);
　　this.lwndC = showVideo.capCreateCaptureWindowA(lpszName, showVideo.WS_VISIBLE + showVideo.WS_CHILD, 0, 0, mWidth, mHeight, mControlPtr, 0);
　　
　　if (this.capDriverConnect(this.lwndC, 0))
　　{
　　this.capPreviewRate(this.lwndC, 66);
　　this.capPreview(this.lwndC, true);
　　showVideo.BITMAPINFO bitmapinfo = new showVideo.BITMAPINFO();
　　bitmapinfo.bmiHeader.biSize = showVideo.SizeOf(bitmapinfo.bmiHeader);
　　bitmapinfo.bmiHeader.biWidth = 352;
　　bitmapinfo.bmiHeader.biHeight = 288;
　　bitmapinfo.bmiHeader.biPlanes = 1;
　　bitmapinfo.bmiHeader.biBitCount = 24;
　　this.capSetVideoFormat(this.lwndC, ref bitmapinfo, showVideo.SizeOf(bitmapinfo));
　　this.mFrameEventHandler = new showVideo.FrameEventHandler(FrameCallBack);
　　this.capSetCallbackOnFrame(this.lwndC, this.mFrameEventHandler);
　　showVideo.SetWindowPos(this.lwndC, 0, 0, 0, mWidth , mHeight , 6);
　　}
　　}
　　// private functions
　　private bool capDriverConnect(IntPtr lwnd, short i)
　　{
　　return showVideo.SendMessage(lwnd, showVideo.WM_CAP_DRIVER_CONNECT, i, 0);
　　}
　　private bool capDriverDisconnect(IntPtr lwnd)
　　{
　　return showVideo.SendMessage(lwnd, showVideo.WM_CAP_DRIVER_DISCONNECT, 0, 0);
　　}
　　
　　private bool capPreview(IntPtr lwnd, bool f)
　　{
　　return showVideo.SendMessage(lwnd, showVideo.WM_CAP_SET_PREVIEW , f, 0);
　　}
　　private bool capPreviewRate(IntPtr lwnd, short wMS)
　　{
　　return showVideo.SendMessage(lwnd, showVideo.WM_CAP_SET_PREVIEWRATE, wMS, 0);
　　}
　　
　　private bool capSetCallbackOnFrame(IntPtr lwnd, showVideo.FrameEventHandler lpProc)
　　{????
　　return showVideo.SendMessage(lwnd, showVideo.WM_CAP_SET_CALLBACK_FRAME, 0, lpProc);
　　}
　　private bool capSetVideoFormat(IntPtr hCapWnd, ref showVideo.BITMAPINFO BmpFormat, int CapFormatSize)
　　{
　　return showVideo.SendMessage(hCapWnd, showVideo.WM_CAP_SET_VIDEOFORMAT, CapFormatSize, ref BmpFormat);
　　}
　　private void FrameCallBack(IntPtr lwnd, IntPtr lpVHdr)
　　{
　　showVideo.VIDEOHDR videoHeader = new showVideo.VIDEOHDR();
　　byte[] VideoData;
　　videoHeader = (showVideo.VIDEOHDR)showVideo.GetStructure(lpVHdr,videoHeader);
　　VideoData = new byte[videoHeader.dwBytesUsed];
　　showVideo.Copy(videoHeader.lpData ,VideoData);
　　if (this.RecievedFrame != null)
　　this.RecievedFrame (VideoData);
　　}
　　}
　　}
　　具体调用如下：
　　using System;
　　using System.Drawing;
　　using System.Collections;
　　using System.ComponentModel;
　　using System.Windows.Forms;
　　using System.Data;
　　using webcam;
　　namespace webcam
　　{
　　///
　　/// Form1 的摘要说明。
　　///
　　public class Form1 : System.Windows.Forms.Form
　　{
　　private System.Windows.Forms.Panel panelPreview;
　　private System.Windows.Forms.Button b_play;
　　private System.Windows.Forms.Button b_stop;
　　///
　　/// 必需的设计器变量。
　　///
　　private System.ComponentModel.Container components = null;
　　WebCamera wc;
　　public Form1()
　　{
　　//
　　// Windows 窗体设计器支持所必需的
　　//
　　InitializeComponent();
　　//
　　// TODO: 在 InitializeComponent 调用后添加任何构造函数代码
　　//
　　}
　　///
　　/// 清理所有正在使用的资源。
　　///
　　protected override void Dispose( bool disposing )
　　{
　　if( disposing )
　　{
　　if (components != null)
　　{
　　components.Dispose();
　　}
　　}
　　base.Dispose( disposing );
　　}
　　#region Windows 窗体设计器生成的代码
　　///
　　/// 设计器支持所需的方法 - 不要使用代码编辑器修改
　　/// 此方法的内容。
　　///
　　private void InitializeComponent()
　　{
　　this.b_play = new System.Windows.Forms.Button();
　　this.panelPreview = new System.Windows.Forms.Panel();
　　this.b_stop = new System.Windows.Forms.Button();
　　this.SuspendLayout();
　　//
　　// b_play
　　//
　　this.b_play.Location = new System.Drawing.Point(280, 368);
　　this.b_play.Name = "b_play";
　　this.b_play.TabIndex = 0;
　　this.b_play.Text = "&Play";
　　this.b_play.Click += new System.EventHandler(this.button1_Click);
　　//
　　// panelPreview
　　//
　　this.panelPreview.Location = new System.Drawing.Point(8, 8);
　　this.panelPreview.Name = "panelPreview";
　　this.panelPreview.Size = new System.Drawing.Size(344, 272);
　　this.panelPreview.TabIndex = 1;
　　//
　　// b_stop
　　//
　　this.b_stop.Enabled = false;
　　this.b_stop.Location = new System.Drawing.Point(360, 368);
　　this.b_stop.Name = "b_stop";
　　this.b_stop.TabIndex = 2;
　　this.b_stop.Text = "&Stop";
　　this.b_stop.Click += new System.EventHandler(this.b_stop_Click);
　　//
　　// Form1
　　//
　　this.AutoScaleBaseSize = new System.Drawing.Size(6, 14);
　　this.ClientSize = new System.Drawing.Size(464, 413);
　　this.Controls.Add(this.b_stop);
　　this.Controls.Add(this.panelPreview);
　　this.Controls.Add(this.b_play);
　　this.MaximizeBox = false;
　　this.MinimizeBox = false;
　　this.Name = "Form1";
　　this.Text = "GoodView test Web Camera";
　　this.Load += new System.EventHandler(this.Form1_Load);
　　this.ResumeLayout(false);
　　}
　　#endregion
　　///
　　/// 应用程序的主入口点。
　　///
　　[STAThread]
　　static void Main()
　　{
　　Application.Run(new Form1());
　　}
　　private void Form1_Load(object sender, System.EventArgs e)
　　{
　　b_play.Enabled = false;
　　b_stop.Enabled = true;
　　panelPreview.Size = new Size(330,330);
　　wc = new WebCamera( panelPreview.Handle,panelPreview.Width,panelPreview.Height);
　　wc.StartWebCam();
　　}
　　private void button1_Click(object sender, System.EventArgs e)
　　{
　　b_play.Enabled = false;
　　b_stop.Enabled = true;
　　panelPreview.Size = new Size(330,330);
　　wc = new WebCamera( panelPreview.Handle,panelPreview.Width,panelPreview.Height);
　　wc.StartWebCam();
　　}
　　private void b_stop_Click(object sender, System.EventArgs e)
　　{
　　b_play.Enabled = true;
　　b_stop.Enabled = false;
　　wc.CloseWebcam();
　　}
　　}
　　}

本文转自
http://blog.youkuaiyun.com/chjk1/articles/109092.aspx