ByteScout Barcode Reader SDK – C# – Read barcodes From Live Video Cam (WPF)

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App.xaml.cs

      
using System;
using System.Collections.Generic;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Windows;

namespace ReadFromVideoCamera.VS2010.WPF
{
    /// <summary>
    /// Interaction logic for App.xaml
    /// </summary>
    public partial class App : Application
    {
        
    }
}

    

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VideoScanForm.xaml.cs

      
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Drawing;
using System.Drawing.Imaging;
using System.IO;
using System.Reflection;
using System.Threading;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Threading;
using Bytescout.BarCodeReader;
using TouchlessLib;

namespace ReadFromVideoCamera.VS2010.WPF
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        // Touchless lib manager object (to use it you should have TouchlessLib.dll and WebCamLib.dll)
        private TouchlessMgr _touchlessMgr;

        // USED IN POPUP MODE ONLY (see ShowScanPopup() method)
        // Close or not on the first barcode found
        // (results are saved in _foundBarcodes)
	    public bool CloseOnFirstBarcodeFound { get; set; }

		// Indicates if the form is closed
		public bool IsClosed { get; set; }

        // Background processing object
        BackgroundWorker _backgroundWorker = new BackgroundWorker();

		// Barcode type to scan
        private BarcodeTypeSelector _barcodeTypeToFind = new BarcodeTypeSelector();

		// Array with decoded barcodes from the last scanning session
		public FoundBarcode[] FoundBarcodes { get; set; }

		// Scanning delay (ms); default is to scan every 800 ms.
		const int ScanDelay = 800;

		// Internal varaible to indicate the status.
        public static bool Status = true;

		public delegate void SimpleDelegate();
		

        /// <summary>
        /// Creates the form.
        /// </summary>
        public MainWindow()
        {
            InitializeComponent();

            lblScanning.Visibility = Visibility.Collapsed;
            
			_backgroundWorker.WorkerSupportsCancellation = true;
			_backgroundWorker.DoWork += BackgroundWorker_DoWork;
			_backgroundWorker.RunWorkerCompleted += BackgroundWorker_RunWorkerCompleted;
        }
		
		// Searches for barcodes in bitmap object
        private FoundBarcode[] FindBarcodes(Bitmap bitmap)
        {
            Reader reader = new Reader();

            try
            {
                reader.RegistrationName = "demo";
                reader.RegistrationKey = "demo";

                this.Dispatcher.Invoke(DispatcherPriority.Normal, (SimpleDelegate) UpdateBarcodeTypeToFindFromCombobox);

                reader.BarcodeTypesToFind = _barcodeTypeToFind;
				
                //reader.MaxNumberOfBarcodesPerPage = 1;

                /* -----------------------------------------------------------------------
                NOTE: We can read barcodes from specific page to increase performance.
                For sample please refer to "Decoding barcodes from PDF by pages" program.
                ----------------------------------------------------------------------- */

                FoundBarcode[] result = reader.ReadFrom(bitmap);
                String timeNow = string.Format("{0:HH:mm:ss:tt}", DateTime.Now);

				this.Dispatcher.Invoke(DispatcherPriority.Normal, (SimpleDelegate) delegate
                      {
                          if (result != null && result.Length > 0)
                          {

                              textAreaBarcodes.SelectAll();
                              textAreaBarcodes.Selection.Text = "\nTime: " + timeNow + "\n";

							  // insert barcodes into text box
                              foreach (FoundBarcode barcode in result)
                              {
								  // make a sound that we found the barcode
                                  Console.Beep();
                                  // form the string with barcode value
                                  String barcodeValue = String.Format("Found: {0} {1}\n", barcode.Type, barcode.Value);
                                  // add barcode to the text area output
                                  textAreaBarcodes.AppendText(barcodeValue + "\n");
                                  // add barcode to the list of saved barcodes
                                  lblFoundBarcodes.Content = String.Format("Found {0} barcodes:", result.Length);
                              }
                          }

						  // make "Scanning..." label flicker
                          lblScanning.Visibility = lblScanning.Visibility == Visibility.Collapsed 
							  ? Visibility.Visible 
							  : Visibility.Collapsed;
                          lblScanning.UpdateLayout();
                      });

				// return found barcodes
                return result;
       
            }
            finally
            {
                reader.Dispose();
            }
        }

        private void Window_Loaded(object sender, RoutedEventArgs e)
        {
            // Populate barcode types into the combobox
            PopulateBarcodeTypesCombobox();

            InitCamera();

            StartDecoding();
        }

        private void InitCamera()
        {
            try
            {
                // Create Touchless lib manager to work with video camera
                _touchlessMgr = new TouchlessMgr();

                // Iterate through available video camera devices
                foreach (Camera camera in _touchlessMgr.Cameras)
                {
                    // Add to list of available camera devices
                    cbCamera.Items.Add(camera);
                }

                // Select first available camera
                cbCamera.SelectedItem = _touchlessMgr.Cameras[0];


                // Setting default image dimensions; see also camera selection event.
                _touchlessMgr.Cameras[0].CaptureWidth = int.Parse(tbCameraWidth.Text);
                _touchlessMgr.Cameras[0].CaptureHeight = int.Parse(tbCameraHeight.Text);

            }
            catch (Exception ex)
            {
                MessageBox.Show("No video camera available. Please connect camera.\n" + ex.Message);
            }
        }

        public void StartDecoding()
        {
            UpdateCameraSelection();

            // Clear the text box output
            TextRange txt = new TextRange(textAreaBarcodes.Document.ContentStart, textAreaBarcodes.Document.ContentEnd);
            txt.Text = "";

            // Clean list of barcodes
            FoundBarcodes = null;

            // Check camera selected
            if (cbCamera.SelectedIndex != -1)
            {
                // Set status
                Status = true;

                // Update UI buttons
                btnStart.IsEnabled = false;
                btnStop.IsEnabled = true;
                cbBarCodeType.IsEnabled = false;
                cbCamera.IsEnabled = false;
                tbCameraHeight.IsEnabled = false;
                tbCameraWidth.IsEnabled = false;
                lblScanning.Content = "Scanning...";

                // Start the decoding thread
                _backgroundWorker.RunWorkerAsync(CloseOnFirstBarcodeFound);
            }
            else
            {
                MessageBox.Show("Please select camera");
            }        
        }
		
        // Update picture box with the latest frame from video camera
        void CurrentCamera_OnImageCaptured(object sender, CameraEventArgs e)
        {
            // You can change image dimensions if needed
            //_touchlessMgr.CurrentCamera.CaptureWidth = 320;
            //_touchlessMgr.CurrentCamera.CaptureHeight = 240;
			Dispatcher.Invoke(DispatcherPriority.Normal, (SimpleDelegate) delegate
				{
					if (_touchlessMgr != null)
					{
						pictureVideoPreview.BeginInit();
						BitmapImage imageSource = BitmapToImageSource(_touchlessMgr.CurrentCamera.GetCurrentImage(), ImageFormat.Png);

						ScaleTransform st = new ScaleTransform();
						st.ScaleX = (double)320 / (double)imageSource.PixelWidth;
						st.ScaleY = (double)240 / (double)imageSource.PixelHeight;
						TransformedBitmap tb = new TransformedBitmap(imageSource, st);

						pictureVideoPreview.Source = tb;
						pictureVideoPreview.EndInit();
						pictureVideoPreview.UpdateLayout();
					}
				});

        }

		// Convert System.Drawing.Bitmap to System.Windows.Media.Imaging.BitmapImage
		BitmapImage BitmapToImageSource(Bitmap bitmap, ImageFormat imageFormat)
        {
            using (MemoryStream memoryStream = new MemoryStream())
            {
                bitmap.Save(memoryStream, imageFormat);
                memoryStream.Position = 0;
                BitmapImage bitmapImage = new BitmapImage();
                bitmapImage.BeginInit();
                bitmapImage.StreamSource = memoryStream;
                bitmapImage.CacheOption = BitmapCacheOption.OnLoad;
                bitmapImage.EndInit();

                return bitmapImage;
            }
        }

        private void btnStart_Click(object sender, RoutedEventArgs e)
        {
            StartDecoding();
        }

        private void btnStop_Click(object sender, RoutedEventArgs e)
        {
            StopDecoding();
        }

        private void StopDecoding()
        {
            _backgroundWorker.CancelAsync();

            // Update UI elements
            lblScanning.Visibility = Visibility.Collapsed;

            // Change working status
            Status = false;

            btnStart.IsEnabled = true;
            btnStop.IsEnabled = false;

            cbBarCodeType.IsEnabled = true;
            cbCamera.IsEnabled = true;

            tbCameraHeight.IsEnabled = true;
            tbCameraWidth.IsEnabled = true;

			if (CloseOnFirstBarcodeFound && FoundBarcodes != null && FoundBarcodes.Length > 0)
				Close();
        }

        public void BackgroundWorker_DoWork(object sender, DoWorkEventArgs e)
        {
			BackgroundWorker worker = (BackgroundWorker) sender;
            bool closeOnFirstBarcode = (bool) e.Argument;

            while (true)
            {
				// Work till user canceled the scan
				if (worker.CancellationPending)
	            {
		            e.Cancel = true;
		            return;
	            }

				// Get current frame bitmap from camera using Touchless lib
	            Bitmap bitmap = _touchlessMgr.CurrentCamera.GetCurrentImage();

	            // Search barcodes
	            FoundBarcode[] result = null;

	            if (bitmap != null)
		            result = FindBarcodes(bitmap);

	            // Check if we need to stop on first barcode found
	            if (closeOnFirstBarcode && result != null && result.Length > 0)
	            {
		            e.Result = result;
		            return; // end processing
	            }

	            // Wait a little to lower CPU load
	            Thread.Sleep(ScanDelay);
            }
        }

        private void BackgroundWorker_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
        {
            // Clear last results
            FoundBarcodes = null;

            if (e.Cancelled)
            {
                lblScanning.Content = "Canceled";
            }
            else if (e.Error != null)
            {
                lblScanning.Content = "Error: " + e.Error.Message;
            }
            else
            {
                lblScanning.Content = "Done.";
                FoundBarcodes = (FoundBarcode[]) e.Result;
            }

            StopDecoding();
        }

        private void cbCamera_SelectionChanged(object sender, SelectionChangedEventArgs e)
        {
            UpdateCameraSelection();
        }

        private void UpdateCameraSelection()
        {
            if (cbCamera.Items.Count > 0 && cbCamera.SelectedIndex >-1)
            {
                if (_touchlessMgr.CurrentCamera != null)
                    _touchlessMgr.CurrentCamera.OnImageCaptured -= CurrentCamera_OnImageCaptured;
                
                _touchlessMgr.CurrentCamera = null;

                Camera currentCamera = _touchlessMgr.Cameras[cbCamera.SelectedIndex];

                // Setting camera output image dimensions
                currentCamera.CaptureWidth = int.Parse(tbCameraWidth.Text);
                currentCamera.CaptureHeight = int.Parse(tbCameraHeight.Text);

                _touchlessMgr.CurrentCamera = currentCamera;
                currentCamera.OnImageCaptured += CurrentCamera_OnImageCaptured;
            }
        }

        // Updates barcode type filter according with combobox selection
        private void UpdateBarcodeTypeToFindFromCombobox()
        {
            string selectedItemText = cbBarCodeType.Text;

            if (string.IsNullOrEmpty(selectedItemText))
                throw new Exception("Empty barcode type selection.");

            _barcodeTypeToFind.Reset();

            // Iterate through BarcodeTypeSelector bool properties 
			// and enable property by barcode name selected in the combobox
			foreach (PropertyInfo propertyInfo in typeof(BarcodeTypeSelector).GetProperties())
            {
                // Skip readonly properties
                if (!propertyInfo.CanWrite)
                    continue;

				if (propertyInfo.Name == selectedItemText)
                    propertyInfo.SetValue(_barcodeTypeToFind, true, null);
            }
        }

        protected void PopulateBarcodeTypesCombobox()
        {
            cbBarCodeType.Items.Clear();
            List <string> items = new List<string>();

			foreach (PropertyInfo propinfo in typeof(BarcodeTypeSelector).GetProperties())
            {
                // Skip readonly properties
                if (!propinfo.CanWrite)
                    continue;

                items.Add(propinfo.Name);
            }
           
			items.Sort();
			cbBarCodeType.ItemsSource = items;

            // Select first item in combobox (first is "Find All")
            cbBarCodeType.SelectedItem = cbBarCodeType.Items[0];
        }

        private void Window_Closing(object sender, CancelEventArgs e)
        {
            Deinitialize();
        }

        private void Deinitialize()
        {
            // cancel decoding thread
            _backgroundWorker.CancelAsync();
            
			// Deinit camera
            DeinitCamera();
            
			// Mark as closed
            IsClosed = true;
        }

        private void btnExit_Click(object sender, RoutedEventArgs e)
        {
            Close();
        }

        private void DeinitCamera()
        {
            if (_touchlessMgr != null)
            {
                _touchlessMgr.CurrentCamera.OnImageCaptured -= CurrentCamera_OnImageCaptured;
                _touchlessMgr.CurrentCamera = null;
            }

            if (cbCamera.SelectedItem != null)
                cbCamera.SelectedItem = null;

            cbCamera.Items.Clear();
            _touchlessMgr = null;

            Thread.Sleep(500);
        }

        private void btnTryPopup_Click(object sender, RoutedEventArgs e)
        {
            // Stop scan if any
			StopDecoding();

            // Deinit the current camera
            DeinitCamera();

            ShowScanPopup();

            // Reinit current camera
            InitCamera();
        }

        private void ShowScanPopup()
        {
			// Create another MainWindow instance to scan barcodes
            MainWindow popup = new MainWindow();
            // Set new popup position shifted by 20 pixels
            popup.Left = Left + 20;
            popup.Top = Top + 20;

            // Set the new popup window to close on first found barcode
            popup.CloseOnFirstBarcodeFound = true;

			// Hide btnTryPopup button 
            popup.btnTryPopup.Visibility = Visibility.Hidden;
            popup.btnStop.Visibility = Visibility.Hidden;
            popup.btnStart.Visibility = Visibility.Hidden;

            // Set the popup title
            popup.Title = "POPUP DIALOG - ONE-TIME SCAN";

            // Show the dialog
            popup.Show();

            // Now wait while the popup is closed (it will be closed on barcode found or canceled)
            while (!popup.IsClosed)
            {
                // HACK: Simulate "DoEvents"
                Dispatcher.Invoke(DispatcherPriority.Background, new ThreadStart(delegate { }));
                Thread.Sleep(20);
            }

            // Checking if one-time scan dialog found barcodes 
            if (popup.FoundBarcodes != null && popup.FoundBarcodes.Length > 0)
                MessageBox.Show("Popup scan found the barcode: \n" + popup.FoundBarcodes[0].Value, "POPUP RESULT");
            else
                MessageBox.Show("Popup canceled. Returning to the main window");

            // Close the dialog
            popup.Close();
        }
    }
}

    

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Explore Web API Docs

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ON-PREMISE OFFLINE SDK

60 Day Free Trial or Visit ByteScout BarCode Reader SDK Home Page

Explore ByteScout BarCode Reader SDK Documentation

Explore Samples

Sign Up for ByteScout BarCode Reader SDK Online Training

ON-DEMAND REST WEB API

Get Your API Key

Explore Web API Docs

Explore Web API Samples