C#学习笔记——摄像头

[code] 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;

//添加引用

using System.Runtime.InteropServices;

using System.Drawing.Imaging;

namespace Camera

{

 public partial class FormMain : Form

{

 WebCamera wc;

 //声明一个API函数 

 [System.Runtime.InteropServices.DllImportAttribute("gdi32.dll")]

private static extern bool BitBlt(

 IntPtr hdcDest, // 目标 DC的句柄 

 int nXDest,

 int nYDest,

 int nWidth,

 int nHeight,

 IntPtr hdcSrc, // 源DC的句柄 

 int nXSrc,

 int nYSrc,

 System.Int32 dwRop // 光栅的处理数值 

 ); 

 public FormMain()

{

 InitializeComponent();

}

 private void btnPlay_Click(object sender, EventArgs e)

{

 btnPlay.Enabled = false;

 btnStop.Enabled = true;

 //panelPreview.Size = new Size(330, 330);

 wc = new WebCamera(panelPreview.Handle, panelPreview.Width, panelPreview.Height);

 wc.StartWebCam();

}

 private void FormMain_Load(object sender, EventArgs e)

{

 btnPlay.Enabled = false;

 btnStop.Enabled = true;

 //panelPreview.Size = new Size(330, 330);

 wc = new WebCamera(panelPreview.Handle, panelPreview.Width, panelPreview.Height);

 wc.StartWebCam();

}

 private void btnStop_Click(object sender, EventArgs e)

{

 btnPlay.Enabled = true;

 btnStop.Enabled = false;

 wc.CloseWebcam();

}

 private void btnPhoto_Click(object sender, EventArgs e)

{

 //创建一个以当前控件区域屏幕为模板的图象 

 Graphics gPanel = this.panelPreview.CreateGraphics(); 

 Bitmap bmSave = new Bitmap(this.panelPreview.Width, this.panelPreview.Height); //用于保存图片的位图对象

 Graphics gSave = Graphics.FromImage(bmSave);

 //得到屏幕的DC 

 IntPtr dcPanel = gPanel.GetHdc();

 //得到Bitmap的DC 

 IntPtr dcSave = gSave.GetHdc();

 //调用此API函数，实现屏幕捕获 

 BitBlt(dcSave, 0, 0, this.panelPreview.Width, this.panelPreview.Height, dcPanel, 0, 0, 13369376);

 //释放掉屏幕的DC 

 gPanel.ReleaseHdc(dcPanel);

 //释放掉Bitmap的DC 

 gSave.ReleaseHdc(dcSave);

 //以JPG文件格式来保存 

 bmSave.Save(@"D:/Photo.jpg", ImageFormat.Jpeg);

 MessageBox.Show("当前图像已经保存为D盘Photo文件！"); 

}

}

//show Video class

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);

}

}

}