Question

用C#如何实现启动摄像头?

Answer 1

安装像头后，一般可以找到一个avicap32.dll文件 这是一个关于像头的类 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 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(); } } }

Answer 2

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using webcam;
using PickHead;
namespace test_avicap
{
public partial class Form1 : Form
{
// WebCamera wc;
Pick pick;
public Form1()
{
InitializeComponent();
}
private void Form1_Load(object sender, 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();
int left=0;
int top=0;
int width=352;
int height=288;
pick = new Pick( panelPreview.Handle, left,top, width, height );
pick.Start();
}
private void b_play_Click(object sender, 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();
int left = 0;
int top = 0;
int width =352;
int height = 288;
pick = new Pick(panelPreview.Handle, left, top, width, height);
pick.Start();
}
private void b_stop_Click(object sender, EventArgs e)
{

//wc.CloseWebcam();
pick.Stop();
}

protected override void OnClosing(CancelEventArgs e)
{
if (MessageBox.Show("退出本系统?", "提示", MessageBoxButtons.OKCancel, MessageBoxIcon.Question) == DialogResult.OK)
Application.Exit();
else
e.Cancel = true;
}
private void b_pic_Click(object sender, EventArgs e)//拍摄
{
if (this.b_pic.Text == "拍摄&A") //用于摄像的
{
b_pic.Text = "重照&C";
string path;
sdf1.Filter = "图片*.bmp;*.jpg;.jpeg;*.gif|*.bmp|所有文件(*.*)|*.*";
if (sdf1.ShowDialog() == DialogResult.OK)
{
path = sdf1.FileName;
pick.GrabImage(path);
pic_show.ImageLocation = path; //并显示在方框中
pic_show.Location = new Point(110, 12);
pic_show.Visible = true;
panelPreview.Visible = false;
pick.Stop();
}
}
else
{
b_pic.Text = "拍摄&A";
pic_show.Visible = false;
panelPreview.Location = new Point(110, 12);
panelPreview.Visible = true;
pick.Start();
}
}
}
}

调用的类(class1.cs)
//本文是借助avicap32.dll库来驱动摄像头。做到了抓图、录像功能。
using System;
using System.Runtime.InteropServices;
using System.Drawing;
using System.Drawing.Imaging;
namespace PickHead
{
///
/// 一个控制摄像头的类
///
public class Pick
{
private const int WM_USER = 0x400;
private const int WS_CHILD = 0x40000000;
private const int WS_VISIBLE = 0x10000000;
private const int WM_CAP_START = WM_USER;
private const int WM_CAP_STOP = WM_CAP_START + 68;
private const int WM_CAP_DRIVER_CONNECT = WM_CAP_START + 10;
private const int WM_CAP_DRIVER_DISCONNECT = WM_CAP_START + 11;
private const int WM_CAP_SAVEDIB = WM_CAP_START + 25;
private const int WM_CAP_GRAB_FRAME = WM_CAP_START + 60;
private const int WM_CAP_SEQUENCE = WM_CAP_START + 62;
private const int WM_CAP_FILE_SET_CAPTURE_FILEA = WM_CAP_START + 20;
private const int WM_CAP_SEQUENCE_NOFILE =WM_CAP_START+ 63;
private const int WM_CAP_SET_OVERLAY =WM_CAP_START+ 51;
private const int WM_CAP_SET_PREVIEW =WM_CAP_START+ 50;
private const int WM_CAP_SET_CALLBACK_VIDEOSTREAM = WM_CAP_START +6;
private const int WM_CAP_SET_CALLBACK_ERROR=WM_CAP_START +2;
private const int WM_CAP_SET_CALLBACK_STATUSA= WM_CAP_START +3;
private const int WM_CAP_SET_CALLBACK_FRAME= WM_CAP_START +5;
private const int WM_CAP_SET_SCALE=WM_CAP_START+ 53;
private const int WM_CAP_SET_PREVIEWRATE=WM_CAP_START+ 52;
private IntPtr hWndC;
private bool bStat = false;
private IntPtr mControlPtr;
private int mWidth;
private int mHeight;
private int mLeft;
private int mTop;
///
/// 初始化摄像头
///
/// 控件的句柄
/// 开始显示的左边距
/// 开始显示的上边距
/// 要显示的宽度
/// 要显示的长度
public Pick(IntPtr handle, int left, int top, int width,int height)
{
mControlPtr = handle;
mWidth = width;
mHeight = height;
mLeft = left;
mTop = top;
}
[DllImport("avicap32.dll")]
private static extern IntPtr capCreateCaptureWindowA(byte[] lpszWindowName, int dwStyle, int x, int y, int nWidth, int nHeight, IntPtr hWndParent, int nID);
[DllImport("avicap32.dll")]
private static extern int capGetVideoFormat(IntPtr hWnd, IntPtr psVideoFormat, int wSize );
[DllImport("User32.dll")]
private static extern bool SendMessage(IntPtr hWnd, int wMsg, int wParam, int lParam);
///
/// 开始显示图像
///
public void Start()
{
if (bStat)
return;
bStat = true;
byte[] lpszName = new byte[100];
hWndC = capCreateCaptureWindowA(lpszName,WS_CHILD|WS_VISIBLE ,mLeft,mTop,mWidth,mHeight,mControlPtr,0);
if (hWndC.ToInt32() != 0)
{
SendMessage(hWndC, WM_CAP_SET_CALLBACK_VIDEOSTREAM, 0, 0);
SendMessage(hWndC, WM_CAP_SET_CALLBACK_ERROR, 0, 0);
SendMessage(hWndC, WM_CAP_SET_CALLBACK_STATUSA, 0, 0);
SendMessage(hWndC, WM_CAP_DRIVER_CONNECT, 0, 0);
SendMessage(hWndC, WM_CAP_SET_SCALE, 1, 0);
SendMessage(hWndC, WM_CAP_SET_PREVIEWRATE, 66, 0);
SendMessage(hWndC, WM_CAP_SET_OVERLAY, 1, 0);
SendMessage(hWndC, WM_CAP_SET_PREVIEW, 1, 0);
}
return;
}
///
/// 停止显示
///
public void Stop()
{
SendMessage(hWndC, WM_CAP_DRIVER_DISCONNECT, 0, 0);
bStat = false;
}
///
/// 抓图
///
/// 要保存bmp文件的路径
public void GrabImage(string path)
// public void GrabImage( )
{
IntPtr hBmp = Marshal.StringToHGlobalAnsi(path);
SendMessage(hWndC,WM_CAP_SAVEDIB,0,hBmp.ToInt32());
}
///
/// 录像
///
/// 要保存avi文件的路径
public void Kinescope(string path)
{
IntPtr hBmp = Marshal.StringToHGlobalAnsi(path);
SendMessage(hWndC,WM_CAP_FILE_SET_CAPTURE_FILEA,0,hBmp.ToInt32());
SendMessage(hWndC, WM_CAP_SEQUENCE, 0, 0);
}
///
/// 停止录像
///
public void StopKinescope()
{
SendMessage(hWndC, WM_CAP_STOP, 0, 0);
}
}
}

Answer 3

启动吗？？？你说的，直接用厂家的接口文件打开设备还是调用安装好的程序来打开设备？