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(English) Capture from webcam in CSharp
Da Programmazione Software.
I want share a class to handle webcam using avicap.ddl (found in windows) in C#, in WPF environment.
This class has made with codes from internet, so i am not the only developer of this code. :-)
At the end of code you will find zip to download with test project, very simple to integrate in your application.
Main class: CaptureDevice.cs
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Runtime.InteropServices;
using System.Windows;
using System.Windows.Controls;
using System.Drawing;
using System.Windows.Media.Imaging;
namespace CamCapture{/// <see cref="http://www.pinvoke.net/default.aspx/Constants.WM"/>public class Constants
{public const uint WM_CAP = 0x400;
public const uint WM_CAP_DRIVER_CONNECT = 0x40a;
public const uint WM_CAP_DRIVER_DISCONNECT = 0x40b;
public const uint WM_CAP_EDIT_COPY = 0x41e;
public const uint WM_CAP_SET_PREVIEW = 0x432;
public const uint WM_CAP_SET_OVERLAY = 0x433;
public const uint WM_CAP_SET_PREVIEWRATE = 0x434;
public const uint WM_CAP_SET_SCALE = 0x435;
public const uint WS_CHILD = 0x40000000;
public const uint WS_VISIBLE = 0x10000000;
}/// <see cref="http://windowssdk.msdn.microsoft.com/en-us/library/ms713477(VS.80).aspx"/>public class Avicap32
{/// <see cref="http://msdn.microsoft.com/library/default.asp?url=/library/en-us/multimed/htm/_win32_capgetdriverdescription.asp"/>[DllImport("avicap32.dll")]
public extern static IntPtr capGetDriverDescription(
ushort index,StringBuilder name,
int nameCapacity,StringBuilder description,
int descriptionCapacity);
/// <see cref="http://msdn.microsoft.com/library/en-us/multimed/htm/_win32_capcreatecapturewindow.asp?frame=true"/>[DllImport("avicap32.dll")]
public extern static IntPtr capCreateCaptureWindow(
string title,uint style,int x,int y,int width,int height,IntPtr window,
int id);
}/// <see cref="http://msdn.microsoft.com/library/default.asp?url=/library/en-us/winui/winui/windowsuserinterface/windowing/messagesandmessagequeues.asp"/>public class User32
{/// <see cref="http://msdn.microsoft.com/library/default.asp?url=/library/en-us/winui/winui/windowsuserinterface/windowing/messagesandmessagequeues/messagesandmessagequeuesreference/messagesandmessagequeuesfunctions/sendmessage.asp"/>[DllImport("user32.dll")]
public static extern IntPtr SendMessage(
IntPtr hWnd,
uint Msg,IntPtr wParam,
IntPtr lParam
);
/// <see cref="http://msdn.microsoft.com/library/default.asp?url=/library/en-us/winui/winui/windowsuserinterface/windowing/windows/windowreference/windowfunctions/setwindowpos.asp"/>[DllImport("user32.dll")]
public static extern IntPtr SetWindowPos(
IntPtr hWnd,
IntPtr hWndInsertAfter,
int X,int Y,int cx,int cy,uint uFlags);
/// <see cref="http://msdn.microsoft.com/library/default.asp?url=/library/en-us/winui/winui/windowsuserinterface/windowing/windows/windowreference/windowfunctions/destroywindow.asp"/>[DllImport("user32")]
public static extern IntPtr DestroyWindow(
IntPtr hWnd
);
}}namespace CamCapture{/// <summary>/// This class represents a device that is capable of capturing audio and video/// </summary>public class CaptureDevice
{private static int MAX_DEVICES = 10;
private ushort deviceNumber;
private string name;
private string description;
private IntPtr deviceHandle;
/// <summary>/// Constructor/// </summary>/// <param name="deviceNumber">the number</param>/// <param name="name">the name</param>/// <param name="description">the description</param>private CaptureDevice(ushort deviceNumber, string name, string description)
{this.deviceNumber = deviceNumber;
this.name = name;
this.description = description;
}/// <summary>/// Setter and Getter for the Device Number/// </summary>public ushort DeviceNumber
{get { return deviceNumber; }
set { deviceNumber = value; }
}/// <summary>/// Setter and Getter for the Device name/// </summary>public string Name
{get { return name; }
set { name = value; }
}/// <summary>/// Setter and Getter for the Device description/// </summary>public string Description
{get { return description; }
set { description = value; }
}/// <summary>/// Attaches the preview stream to the given control/// </summary>/// <param name="control">the control</param>public void Attach(System.Windows.Forms.PictureBox control)
{deviceHandle = Avicap32.capCreateCaptureWindow("", Constants.WS_VISIBLE | Constants.WS_CHILD, 0, 0, control.Width, control.Height, control.Handle, 0);
if (User32.SendMessage(deviceHandle, Constants.WM_CAP_DRIVER_CONNECT, (IntPtr)deviceNumber, (IntPtr)0).ToInt32() > 0)
{User32.SendMessage(deviceHandle, Constants.WM_CAP_SET_SCALE, (IntPtr)(-1), (IntPtr)0);
User32.SendMessage(deviceHandle, Constants.WM_CAP_SET_PREVIEWRATE, (IntPtr)0x42, (IntPtr)0);
User32.SendMessage(deviceHandle, Constants.WM_CAP_SET_PREVIEW, (IntPtr)(-1), (IntPtr)0);
User32.SetWindowPos(deviceHandle, new IntPtr(0), 0, 0, control.Width, control.Height, 6);
}}/// <summary>/// Detaches from the control/// </summary>public void Detach()
{if (deviceHandle.ToInt32() != 0)
{User32.SendMessage(deviceHandle, Constants.WM_CAP_DRIVER_DISCONNECT, (IntPtr)deviceNumber, (IntPtr)0);
User32.DestroyWindow(deviceHandle);
}deviceHandle = new IntPtr(0);
}/// <summary>/// Returns a captured image/// </summary>/// <returns>an image, null if capture failed</returns>public BitmapSource Capture()
{if (deviceHandle.ToInt32() != 0)
{User32.SendMessage(deviceHandle, Constants.WM_CAP_EDIT_COPY, (IntPtr)0, (IntPtr)0);
BitmapSource bs = Clipboard.GetImage();
return bs;
/*IDataObject ido = Clipboard.GetDataObject();if (ido.GetDataPresent(DataFormats.Bitmap)){Bitmap bmp = ((Bitmap)ido.GetData(DataFormats.Bitmap));return ((Bitmap)ido.GetData(DataFormats.Bitmap));}*/}return null;
}/// <summary>/// Returns an array with available capture devices/// </summary>/// <returns>the device names</returns>public static List<CaptureDevice> GetDevices()
{List<CaptureDevice> devices = new List<CaptureDevice>();
for (ushort i = 0; i < MAX_DEVICES; ++i)
{int capacity = 200;
StringBuilder name = new StringBuilder(capacity);
StringBuilder description = new StringBuilder(capacity);
if (Avicap32.capGetDriverDescription(i, name, capacity, description, capacity).ToInt32() > 0)
{devices.Add(new CaptureDevice(i, name.ToString(), description.ToString()));
}}return devices;
}}}
