安装摄像头后，一般可以找到一个avicap32.dll文件
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(); } }}
原著
