C#获取摄像头拍照显示图像

Posted 2021-06-23 dotNET跨平台

概述

之前有个需求，就是在web界面可以实现调用摄像头，用户把手机的个人二维码展示给摄像头，摄像头进行摄像识别用户。

其实本质就是保存图像二维码，在进行二维码识别。

下面来看看如何实现。

主要代码实现

1、初始化摄像头

 /// <summary> /// 初始化摄像头 /// </summary> /// <param name="handle">控件的句柄</param> /// <param name="left">开始显示的左边距</param> /// <param name="top">开始显示的上边距</param> /// <param name="width">要显示的宽度</param> /// <param name="height">要显示的长度</param> 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, long lParam);

2、开始显示图像

 /// <summary> /// 开始显示图像 /// </summary> 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;
 }

3、停止显示

 /// <summary> /// 停止显示


 /// </summary> public void Stop() { SendMessage(hWndC, WM_CAP_DRIVER_DISCONNECT, 0, 0); bStat = false; }

4、抓图

 /// <summary> /// 抓图 /// </summary> /// <param name="path">要保存bmp文件的路径</param> public void GrabImage(string path) {
 IntPtr hBmp = Marshal.StringToHGlobalAnsi(path); SendMessage(hWndC, WM_CAP_SAVEDIB, 0, hBmp.ToInt64());
 }
 /// <summary> /// 录像 /// </summary> /// <param name="path">要保存avi文件的路径</param> public void Kinescope(string path) { IntPtr hBmp = Marshal.StringToHGlobalAnsi(path); SendMessage(hWndC, WM_CAP_FILE_SET_CAPTURE_FILEA, 0, hBmp.ToInt64()); SendMessage(hWndC, WM_CAP_SEQUENCE, 0, 0); }
 /// <summary> /// 停止录像 /// </summary> public void StopKinescope() { SendMessage(hWndC, WM_CAP_STOP, 0, 0); }

完整代码

using System;using System.Collections;using System.Configuration;using System.Data;using System.Linq;using System.Web;using System.Web.Security;using System.Web.UI;using System.Web.UI.htmlControls;using System.Web.UI.WebControls;using System.Web.UI.WebControls.WebParts;using System.Xml.Linq;using System.Windows.Forms;
using System.Runtime.InteropServices;
using com.google.zxing.qrcode.decoder;using com.google.zxing.client;using com.google.zxing.common;
using System.Threading;
public partial class Decode : System.Web.UI.Page{ // public delegate void SaveImg(Pick Pick1); /// <summary> /// 一个控制摄像头的类 /// </summary> 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;
 
 /// <summary> /// 初始化摄像头 /// </summary> /// <param name="handle">控件的句柄</param> /// <param name="left">开始显示的左边距</param> /// <param name="top">开始显示的上边距</param> /// <param name="width">要显示的宽度</param> /// <param name="height">要显示的长度</param> 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, long lParam);
 /// <summary> /// 开始显示图像 /// </summary> 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;
 }
 /// <summary> /// 停止显示


 /// </summary> public void Stop(){ SendMessage(hWndC, WM_CAP_DRIVER_DISCONNECT, 0, 0); bStat = false; } /// <summary> /// 抓图 /// </summary> /// <param name="path">要保存bmp文件的路径</param> public void GrabImage(string path){
 IntPtr hBmp = Marshal.StringToHGlobalAnsi(path); SendMessage(hWndC, WM_CAP_SAVEDIB, 0, hBmp.ToInt64());
 }
 /// <summary> /// 录像 /// </summary> /// <param name="path">要保存avi文件的路径</param> public void Kinescope(string path){ IntPtr hBmp = Marshal.StringToHGlobalAnsi(path); SendMessage(hWndC, WM_CAP_FILE_SET_CAPTURE_FILEA, 0, hBmp.ToInt64()); SendMessage(hWndC, WM_CAP_SEQUENCE, 0, 0); }
 /// <summary> /// 停止录像 /// </summary> public void StopKinescope(){ SendMessage(hWndC, WM_CAP_STOP, 0, 0); }
 }

 protected void Page_Load(object sender, EventArgs e){  } //void DoInit() //{ // System.Windows.Forms.Form frm = new Form(); // frm.Height = 300; // frm.Width = 300; // System.Windows.Forms.PictureBox Panel = new System.Windows.Forms.PictureBox(); // Panel.Height = 300; // Panel.Width = 300; // Panel.Visible = true; // Panel.BackgroundImageLayout = ImageLayout.None; // frm.Controls.Add(Panel); // frm.TopMost = true; // Pick p = new Pick(Panel.Handle, 0, 0, 300, 300); // p.Start(); // frm.Show(); // p.Kinescope(Server.MapPath("img\\Decode2.avi")); // p.GrabImage(Server.MapPath("img\\Decode1.bmp")); // p.Stop(); // frm.Close(); // frm.Dispose(); //}　　 private void getQrcode(){ try {  //ThreadStart worker = new ThreadStart(DoInit); //Thread th = new Thread(worker); //th.IsBackground = true; //th.Start(); System.Windows.Forms.Form frm = new Form(); frm.Height = 300; frm.Width = 300; System.Windows.Forms.PictureBox Panel = new System.Windows.Forms.PictureBox(); Panel.Height = 300; Panel.Width = 300; Panel.Visible = true; Panel.BackgroundImageLayout = ImageLayout.None; frm.Controls.Add(Panel); frm.TopMost = true; Pick p = new Pick(Panel.Handle, 0, 0, 300, 300); p.Start(); int i = 1; while (i <= 1) { p.GrabImage(Server.MapPath("img\\Decode.bmp")); p.Kinescope(Server.MapPath("img\\Video.avi")); i++; } p.Stop(); frm.Close(); frm.Dispose(); try { com.google.zxing.qrcode.QRCodeReader d = new com.google.zxing.qrcode.QRCodeReader(); RGBLuminanceSource rg = new RGBLuminanceSource(new System.Drawing.Bitmap(Server.MapPath("img\\Decode.bmp")), new System.Drawing.Bitmap(Server.MapPath("img\\Decode.bmp")).Width, new System.Drawing.Bitmap(Server.MapPath("img\\Decode.bmp")).Height); com.google.zxing.LuminanceSource ls = rg; HybridBinarizer hb = new HybridBinarizer(ls); com.google.zxing.BinaryBitmap bm = new com.google.zxing.BinaryBitmap(hb); com.google.zxing.Result r = d.decode(bm); TextBox1.Text = r.Text; 
 } catch (Exception ex) {
 TextBox1.Text = ""; //MessageBox.Show(ex.Message+"111");
 throw new Exception(ex.Message); }
  } catch (Exception ee) { ee.ToString(); } } protected void Timer1_Tick(object sender, EventArgs e){ //getQrcode(); } protected void Button1_Click(object sender, EventArgs e){ getQrcode(); }
}