DC_Initlizer/AwInitilizer/KeyinListener.cs

using AwInitilizer.Model;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Input;
using System.Windows.Threading;

namespace AwInitilizer
{
    public class KeyinListener
    {
        public event EventHandler<SystemID> OnSystemIDReseived;

        private string stackedInput = string.Empty;
        private bool shiftPressed = false;
        private DispatcherTimer CleanInputTimer;

        private Window sourceWindow;

        public KeyinListener(Window sourceWindow)
        {
            this.sourceWindow = sourceWindow;
            sourceWindow.Closing += SourceWindow_Closing;
            sourceWindow.PreviewKeyDown += MainWindow_PreviewKeyDown;
            sourceWindow.PreviewKeyUp += MainWindow_PreviewKeyUp;

            CleanInputTimer = new DispatcherTimer();
            CleanInputTimer.Interval = TimeSpan.FromSeconds(1);
            CleanInputTimer.Tick += CleanInputTimer_Tick;
        }

        private void MainWindow_PreviewKeyDown(object sender, KeyEventArgs e)
        {
            if (e.Key == Key.LeftShift || e.Key == Key.RightShift)
            {
                shiftPressed = true;
                return;
            }
            else if (e.Key == Key.Capital)
            {
                shiftPressed = !shiftPressed;
                return;
            }
            else if (e.Key == Key.Enter)
            {
                e.Handled = true;
                return;
            }
            else
            {
                if (e.Key >= Key.D0 && e.Key <= Key.D9)
                {
                    // Number keys pressed so need to so special processing
                    // also check if shift pressed
                    var input = e.Key.ToString();
                    input = input.Remove(0, 1);
                    stackedInput += input;
                }
                else if (e.Key == Key.OemMinus)
                {
                    stackedInput += "-";
                }
                else if (e.Key == Key.Return)
                {
                    return;
                }
                else
                {
                    var input = e.Key.ToString();
                    if (shiftPressed)
                        input = input.ToUpper();
                    stackedInput += input;
                }
            }

            CleanInputTimer.Stop();
            CleanInputTimer.Start();
        }

        private void MainWindow_PreviewKeyUp(object sender, KeyEventArgs e)
        {
            if (e.Key == Key.LeftShift || e.Key == Key.RightShift)
            {
                shiftPressed = false;
            }
        }

        private void CleanInputTimer_Tick(object sender, EventArgs e)
        {
            CleanInputTimer.Stop();

            if (SystemID.TryParse(stackedInput, out SystemID systemID))
            {
                OnSystemIDReseived?.Invoke(this, systemID);
                //SystemIDScanReseived(systemID);
            }

            stackedInput = string.Empty;
        }

        private void SourceWindow_Closing(object sender, System.ComponentModel.CancelEventArgs e)
        {
            try
            {
                sourceWindow.Closing -= SourceWindow_Closing;
                sourceWindow.PreviewKeyDown -= MainWindow_PreviewKeyDown;
                sourceWindow.PreviewKeyUp -= MainWindow_PreviewKeyUp;

                CleanInputTimer.Tick -= CleanInputTimer_Tick;
                CleanInputTimer.Stop();
            }
            catch
            {

            }
        }
    }
}