MainForm.cs
using System;
using System.ComponentModel;
using System.Drawing;
using System.Media;
using System.Reflection;
using System.Text;
using System.Windows.Forms;
using System.Threading;
using Bytescout.BarCodeReader;
using TouchlessLib;
namespace ReadFromVideoCamera
{
public partial class MainForm: Form
{
// Scan delay, ms.
const int SCAN_DELAY = 1500; // scan barcodes every 1.5 sec
// Touchless SDK library manager (to use it you should have TouchlessLib.dll referenced and WebCamLib.dll in the build output directory)
readonly TouchlessMgr _touchlessLibManager;
// Background thread for barcode scanning
readonly BackgroundWorker _backgroundWorker = new BackgroundWorker();
// Synchronization event
readonly AutoResetEvent _synchronizationEvent = new AutoResetEvent(false);
// Form constructor
public MainForm()
{
InitializeComponent();
// Create Touchless library manager
_touchlessLibManager = new TouchlessMgr();
// Setup background worker
_backgroundWorker.WorkerSupportsCancellation = true;
_backgroundWorker.DoWork += BackgroundWorker_DoWork;
_backgroundWorker.RunWorkerCompleted += BackgroundWorker_RunWorkerCompleted;
}
// On form loading
private void Form_Load(object sender, EventArgs e)
{
// Fill devices combobox with available video cameras
foreach (Camera camera in _touchlessLibManager.Cameras)
cmbCamera.Items.Add(camera);
// Select the first available camera. See also cmbCamera_SelectedIndexChanged event handler.
if (_touchlessLibManager.Cameras.Count > 0)
cmbCamera.SelectedItem = _touchlessLibManager.Cameras[0];
else
MessageBox.Show("No video camera available. Please connect the camera.");
// Populate barcode types combobox
PopulateBarcodeTypesCombobox();
// Select some default barcode type
cmbBarcodeType.SelectedItem = "QRCode";
}
protected void PopulateBarcodeTypesCombobox()
{
cmbBarcodeType.Items.Clear();
foreach (PropertyInfo propertyInfo in typeof(BarcodeTypeSelector).GetProperties())
cmbBarcodeType.Items.Add(propertyInfo.Name);
}
// On camera selected
private void cmbCamera_SelectedIndexChanged(object sender, EventArgs e)
{
if (_touchlessLibManager.CurrentCamera != null)
_touchlessLibManager.CurrentCamera.OnImageCaptured -= CurrentCamera_OnImageCaptured;
if (cmbCamera.SelectedIndex != -1)
{
Camera camera = _touchlessLibManager.Cameras[cmbCamera.SelectedIndex];
if (camera != null)
{
// Set camera output image dimensions
camera.CaptureWidth = int.Parse(tbCameraWidth.Text);
camera.CaptureHeight = int.Parse(tbCameraHeight.Text);
camera.OnImageCaptured += CurrentCamera_OnImageCaptured;
// Select the camera
_touchlessLibManager.CurrentCamera = camera;
}
}
}
private void btnUpdateCameraImageDimensions_Click(object sender, EventArgs e)
{
if (_touchlessLibManager.CurrentCamera != null)
{
// Update camera's output image dimensions
_touchlessLibManager.CurrentCamera.CaptureWidth = int.Parse(tbCameraWidth.Text);
_touchlessLibManager.CurrentCamera.CaptureHeight = int.Parse(tbCameraHeight.Text);
}
}
public void StartDecoding()
{
if (cmbCamera.SelectedIndex == -1)
return;
// Clear the output text box
rtbFoundBarcodes.Clear();
// Check if we have camera selected
if (cmbCamera.SelectedIndex != -1)
{
// Start the decoding in the background thread
BarcodeTypeSelector barcodeTypesToFind = GetBarcodeTypeFromCombobox();
_backgroundWorker.RunWorkerAsync(barcodeTypesToFind);
UpdateControls(true);
}
else
{
MessageBox.Show("Please select the camera first!");
}
}
private void StopDecoding()
{
_backgroundWorker.CancelAsync();
// Wait until BackgroundWorker finished
if (_backgroundWorker.IsBusy)
_synchronizationEvent.WaitOne();
UpdateControls(false);
}
void UpdateControls(bool started)
{
if (started)
{
btnStart.Enabled = false;
btnStop.Enabled = true;
cmbBarcodeType.Enabled = false;
cmbCamera.Enabled = false;
tbCameraHeight.Enabled = false;
tbCameraWidth.Enabled = false;
btnUpdateCameraImageDimensions.Enabled = false;
cbStopOnFirstBarcode.Enabled = false;
lblScanning.Visible = true;
lblScanning.Text = "Scanning...";
}
else
{
btnStart.Enabled = true;
btnStop.Enabled = false;
cmbBarcodeType.Enabled = true;
cmbCamera.Enabled = true;
cbStopOnFirstBarcode.Enabled = true;
tbCameraHeight.Enabled = true;
tbCameraWidth.Enabled = true;
btnUpdateCameraImageDimensions.Enabled = true;
lblScanning.Visible = true;
}
}
void CurrentCamera_OnImageCaptured(object sender, CameraEventArgs e)
{
pictureBoxPreview.Image = e.Image;
}
private void btnStart_Click(object sender, EventArgs e)
{
StartDecoding();
}
private void btnStop_Click(object sender, EventArgs e)
{
StopDecoding();
}
// Background thread procedure used by BackgroundWorker
public void BackgroundWorker_DoWork(object sender, DoWorkEventArgs e)
{
BackgroundWorker worker = (BackgroundWorker) sender;
BarcodeTypeSelector barcodeTypesToFind = (BarcodeTypeSelector) e.Argument;
// Create and setup barcode reader instance
using (Reader reader = new Reader())
{
reader.RegistrationName = "demo";
reader.RegistrationKey = "demo";
reader.BarcodeTypesToFind = barcodeTypesToFind;
// Work while not canceled
while (true)
{
// Check cancellation
if (worker.CancellationPending)
{
e.Cancel = true;
_synchronizationEvent.Set();
return;
}
// Get image from camera by invoking method from UI thread
Bitmap bitmap = (Bitmap) Invoke(new GetCameraImageDelegate(GetCameraImage));
if (bitmap == null)
{
e.Result = null;
return;
}
// Search the image for barcodes
FoundBarcode[] result = reader.ReadFrom(bitmap);
// Update UI asynchronously
BeginInvoke(new Action<FoundBarcode[]>(UpdateStatus), new object[] { result });
// Pause
Thread.Sleep(SCAN_DELAY);
}
}
}
delegate Bitmap GetCameraImageDelegate();
Bitmap GetCameraImage()
{
if (!IsDisposed && !Disposing && _touchlessLibManager.CurrentCamera != null)
return _touchlessLibManager.CurrentCamera.GetCurrentImage();
return null;
}
// Update UI with found barcodes information
void UpdateStatus(FoundBarcode[] foundBarcodes)
{
if (foundBarcodes != null && foundBarcodes.Length > 0)
{
// Play sound if we found any barcode
SystemSounds.Beep.Play();
StringBuilder stringBuilder = new StringBuilder();
stringBuilder.AppendFormat("Time: {0:HH:mm:ss:tt}", DateTime.Now);
stringBuilder.AppendLine();
// Display found barcodes in the output text box
foreach (FoundBarcode barcode in foundBarcodes)
{
stringBuilder.AppendFormat("Found barcode: {0} {1}", barcode.Type, barcode.Value);
stringBuilder.AppendLine();
}
rtbFoundBarcodes.Text = stringBuilder.ToString();
// Update status text with number of found barcodes
lblFoundBarcodes.Text = string.Format("Found {0} barcodes:", foundBarcodes.Length);
}
// Make "Scanning..." label flicker.
lblScanning.Visible = !lblScanning.Visible;
lblScanning.Refresh();
// Check if we need to stop on first barcode found
if (cbStopOnFirstBarcode.Checked && foundBarcodes != null && foundBarcodes.Length > 0)
{
StopDecoding();
}
}
// Background thread is finished
private void BackgroundWorker_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
{
// Update UI asynchronously
BeginInvoke(new Action<RunWorkerCompletedEventArgs>(OnBackgroundWorkerFinished), new object[] { e });
}
void OnBackgroundWorkerFinished(RunWorkerCompletedEventArgs completedEventArgs)
{
if (completedEventArgs.Cancelled)
{
lblScanning.Text = "Stopped";
}
else if (completedEventArgs.Error != null)
{
lblScanning.Text = "Error: " + completedEventArgs.Error.Message;
}
else
{
lblScanning.Text = "Done!";
}
UpdateControls(false);
}
// Gets selected barcode type
private BarcodeTypeSelector GetBarcodeTypeFromCombobox()
{
BarcodeTypeSelector result = new BarcodeTypeSelector();
string selectedBarcodeTypeName = (string) cmbBarcodeType.SelectedItem;
PropertyInfo propertyInfo = typeof(BarcodeTypeSelector).GetProperty(selectedBarcodeTypeName);
propertyInfo.SetValue(result, true, null);
return result;
}
protected override void OnClosing(CancelEventArgs e)
{
StopDecoding();
_touchlessLibManager.Dispose();
base.OnClosing(e);
}
private void btnExit_Click(object sender, EventArgs e)
{
DialogResult = DialogResult.OK;
Close();
}
private void btnCameraProperties_Click(object sender, EventArgs e)
{
try
{
if (_touchlessLibManager.CurrentCamera != null)
_touchlessLibManager.CurrentCamera.ShowPropertiesDialog(Handle);
}
catch (Exception exception)
{
MessageBox.Show(exception.Message);
}
}
}
}
Program.cs
using System;
using System.Windows.Forms;
namespace ReadFromVideoCamera
{
static class Program
{
/// <summary>
/// The main entry point for the application.
/// </summary>
[MTAThread]
static void Main()
{
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
MainForm dlg = new MainForm();
dlg.ShowDialog();
}
}
}