我正在开发一个应用程序来控制我公司的食堂消费。基本上每个员工都有一个带有条形码的徽章 ID，他们每天都有权免费用餐。该应用程序将扫描徽章并记录每位员工的用餐情况。它将在具有集成扫描仪并在 Windows CE 上运行的摩托罗拉 MK4000 设备上运行。
我的设备扫描仪有问题。我可以让它运行并正常扫描，但如果它保持空闲几分钟，它会进入“等待”状态，激光关闭，并且不会重新打开。我已经尝试监视状态并在它更改为该状态时开始新的读取，但它只是无限期地继续扫描错误读取。
你们能帮我弄清楚我做错了什么吗？
这是我用于扫描仪功能的类。它不是由我开发的，但它开始用于同一设备上的其他应用程序（我对其进行了一些更改，主要是在错误消息上）。
using System;
using System.Linq;
using System.Collections.Generic;
using System.Text;
using System.Windows.Forms;
namespace MK4000
{
class BarCode
{
#region Fields
private Symbol.Barcode.Reader myReader = null;
private Symbol.Barcode.ReaderData myReaderData = null;
private System.EventHandler myReadNotifyHandler = null;
private System.EventHandler myStatusNotifyHandler = null;
#endregion Fields
#region Properties
/// <summary>
/// Provides the access to the Symbol.Barcode.Reader reference.
/// The user can use this reference for his additional Reader - related operations.
/// </summary>
public Symbol.Barcode.Reader Reader
{
get
{
return myReader;
}
}
public String ErrorMessage
{
get
{
return "Error";
}
}
#endregion Properties
#region Methods
/// <summary>
/// Attach a ReadNotify handler.
/// </summary>
public void AttachReadNotify(System.EventHandler ReadNotifyHandler)
{
// If we have a reader
if (myReader != null)
{
// Attach the read notification handler.
myReader.ReadNotify += ReadNotifyHandler;
myReadNotifyHandler = ReadNotifyHandler;
}
}
/// <summary>
/// Attach a StatusNotify handler.
/// </summary>
public void AttachStatusNotify(System.EventHandler StatusNotifyHandler)
{
// If we have a reader
if (myReader != null)
{
// Attach status notification handler.
myReader.StatusNotify += StatusNotifyHandler;
myStatusNotifyHandler = StatusNotifyHandler;
}
}
/// <summary>
/// Detach the ReadNotify handler.
/// </summary>
public void DetachReadNotify()
{
if ((myReader != null) && (myReadNotifyHandler != null))
{
// Detach the read notification handler.
myReader.ReadNotify -= myReadNotifyHandler;
myReadNotifyHandler = null;
}
}
/// <summary>
/// Detach a StatusNotify handler.
/// </summary>
public void DetachStatusNotify()
{
// If we have a reader registered for receiving the status notifications
if ((myReader != null) && (myStatusNotifyHandler != null))
{
// Detach the status notification handler.
myReader.StatusNotify -= myStatusNotifyHandler;
myStatusNotifyHandler = null;
}
}
/// <summary>
/// Initialize the reader.
/// </summary>
public bool InitReader()
{
// If the reader is already initialized then fail the initialization.
if (myReader != null)
{
return false;
}
else // Else initialize the reader.
{
try
{
// Get the device selected by the user.
Symbol.Generic.Device MyDevice =
Symbol.StandardForms.SelectDevice.Select(
Symbol.Barcode.Device.Title,
Symbol.Barcode.Device.AvailableDevices);
if (MyDevice == null)
{
MessageBox.Show(ErrorMessage);
return false;
}
// Create the reader, based on selected device.
myReader = new Symbol.Barcode.Reader(MyDevice);
// Create the reader data.
myReaderData = new Symbol.Barcode.ReaderData(
Symbol.Barcode.ReaderDataTypes.Text,
Symbol.Barcode.ReaderDataLengths.MaximumLabel);
// Enable the Reader.
myReader.Actions.Enable();
// In this sample, we are setting the aim type to trigger.
switch (myReader.ReaderParameters.ReaderType)
{
case Symbol.Barcode.READER_TYPE.READER_TYPE_IMAGER:
myReader.ReaderParameters.ReaderSpecific.ImagerSpecific.AimType = Symbol.Barcode.AIM_TYPE.AIM_TYPE_TRIGGER;
//myReader.Parameters.Feedback.Success.BeepTime = 0;
break;
case Symbol.Barcode.READER_TYPE.READER_TYPE_LASER:
myReader.ReaderParameters.ReaderSpecific.LaserSpecific.AimType = Symbol.Barcode.AIM_TYPE.AIM_TYPE_TRIGGER;
break;
case Symbol.Barcode.READER_TYPE.READER_TYPE_CONTACT:
// AimType is not supported by the contact readers.
break;
}
myReader.Actions.SetParameters();
}
catch (Symbol.Exceptions.OperationFailureException ex)
{
MessageBox.Show(ex.Message);
return false;
}
catch (Symbol.Exceptions.InvalidRequestException ex)
{
MessageBox.Show(ex.Message);
return false;
}
catch (Symbol.Exceptions.InvalidIndexerException ex)
{
MessageBox.Show(ex.Message);
return false;
};
return true;
}
}
/// <summary>
/// Start a read on the reader.
/// </summary>
public void StartRead(bool toggleSoftTrigger)
{
// If we have both a reader and a reader data
if ((myReader != null) &&
(myReaderData != null))
try
{
if (!myReaderData.IsPending)
{
// Submit a read.
myReader.Actions.Read(myReaderData);
if (toggleSoftTrigger && myReader.Info.SoftTrigger == false)
{
myReader.Info.SoftTrigger = true;
}
}
}
catch (Symbol.Exceptions.OperationFailureException ex)
{
MessageBox.Show(ex.Message);
}
catch (Symbol.Exceptions.InvalidRequestException ex)
{
MessageBox.Show(ex.Message);
}
catch (Symbol.Exceptions.InvalidIndexerException ex)
{
MessageBox.Show(ex.Message);
};
}
/// <summary>
/// Stop all reads on the reader.
/// </summary>
public void StopRead()
{
//If we have a reader
if (myReader != null)
{
try
{
// Flush (Cancel all pending reads).
if (myReader.Info.SoftTrigger == true)
{
myReader.Info.SoftTrigger = false;
}
myReader.Actions.Flush();
}
catch (Symbol.Exceptions.OperationFailureException ex)
{
MessageBox.Show(ex.Message);
}
catch (Symbol.Exceptions.InvalidRequestException ex)
{
MessageBox.Show(ex.Message);
}
catch (Symbol.Exceptions.InvalidIndexerException ex)
{
MessageBox.Show(ex.Message);
};
}
}
/// <summary>
/// Stop reading and disable/close the reader.
/// </summary>
public void TermReader()
{
// If we have a reader
if (myReader != null)
{
try
{
// stop all the notifications.
StopRead();
//Detach all the notification handler if the user has not done it already.
DetachReadNotify();
DetachStatusNotify();
// Disable the reader.
myReader.Actions.Disable();
// Free it up.
myReader.Dispose();
// Make the reference null.
myReader = null;
}
catch (Symbol.Exceptions.OperationFailureException ex)
{
MessageBox.Show(ex.Message);
}
catch (Symbol.Exceptions.InvalidRequestException ex)
{
MessageBox.Show(ex.Message);
}
catch (Symbol.Exceptions.InvalidIndexerException ex)
{
MessageBox.Show(ex.Message);
};
}
// After disposing the reader, dispose the reader data.
if (myReaderData != null)
{
try
{
// Free it up.
myReaderData.Dispose();
// Make the reference null.
myReaderData = null;
}
catch (Symbol.Exceptions.OperationFailureException ex)
{
MessageBox.Show(ex.Message);
}
catch (Symbol.Exceptions.InvalidRequestException ex)
{
MessageBox.Show(ex.Message);
}
catch (Symbol.Exceptions.InvalidIndexerException ex)
{
MessageBox.Show(ex.Message);
};
}
}
#endregion Methods
}
}
这是实际表单的代码：
using System;
using System.Linq;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
namespace MK4000
{
public partial class Form1 : Form
{
private bool isReaderInitiated;
private BarCode myScanner;
private EventHandler myStatusNotifyHandler = null;
private EventHandler myReadNotifyHandler = null;
private String MacAddress = "00-00-00-00-00-00";
private String strIPAddress = "000.000.000.000";
private String version = "0.0.0.1";
public static int TaskbarHeight = Screen.PrimaryScreen.Bounds.Height - Screen.PrimaryScreen.WorkingArea.Height;
private int counter = 0;
private int itemLimit = 10;
public String ErrorMessage
{
get
{
return "Error";
}
}
public Form1()
{
InitializeComponent();
this.Width = Screen.PrimaryScreen.Bounds.Width;
this.Height = Screen.PrimaryScreen.Bounds.Height - TaskbarHeight;
this.FormBorderStyle = FormBorderStyle.None;
this.ControlBox = false;
this.MinimizeBox = false;
this.EmpID.Visible = false;
this.EmpName.Visible = false;
this.messageLabel.Visible = false;
this.lblCounter.Text = counter.ToString();
this.lblCounter.Visible = false;
this.statusBar1.Text = "Initializing.. Reticulating Splines " + MacAddress + " | " + strIPAddress + " | " + version;
this.listView1.View = View.Details;
this.listView1.Columns.Add("EmployeeID", 150, HorizontalAlignment.Left);
this.listView1.Columns.Add("EmployeeName", 330, HorizontalAlignment.Left);
this.listView1.Columns.Add("Time", 250, HorizontalAlignment.Left);
this.Closing += new CancelEventHandler(Form1_OnClosing);
this.myScanner = new BarCode();
this.isReaderInitiated = this.myScanner.InitReader();
if (!(this.isReaderInitiated))// If the reader has not been initialized
{
// Display a message & exit the application.
MessageBox.Show(ErrorMessage);
Application.Exit();
}
else // If the reader has been initialized
{
// Attach a status natification handler.
myScanner.AttachStatusNotify(myScanner_StatusNotify);
// Start a read operation & attach a handler.
myScanner.StartRead(true);
myScanner.AttachReadNotify(myScanner_ReadNotify);
}
}
private void myScanner_ReadNotify(object Sender, EventArgs e)
{
// Get ReaderData
Symbol.Barcode.ReaderData TheReaderData = this.myScanner.Reader.GetNextReaderData();
processData(TheReaderData.ToString());
this.myScanner.StopRead();
System.Threading.Thread.Sleep(1000);
this.myScanner.StartRead(true);
}
private void processData(string readerData)
{
string EmployeeName = "";
string EmployeeID = readerData;
hideMessage();
//This will query the employee database and proceed if employee exists, right now i just give it a random name
EmployeeName = "John Doe";
if (EmployeeName != "")
{
addToList(EmployeeID, EmployeeName);
counter += 1;
this.lblCounter.Text = counter.ToString();
this.EmpID.Visible = true
this.EmpName.Visible = true
this.lblCounter.Visible = true;
showMessage("Thank You!", System.Drawing.Color.LimeGreen);
}
}
private void showMessage(string messageText, System.Drawing.Color messageColor)
{
this.messageLabel.Text = messageText;
this.messageLabel.BackColor = messageColor;
this.messageLabel.Visible = true;
}
private void hideMessage()
{
this.messageLabel.Text = "";
this.messageLabel.BackColor = System.Drawing.Color.Black;
this.messageLabel.Visible = false;
}
private void addToList(string EmployeeID, string EmployeeName)
{
if (this.listView1.Items.Count >= itemLimit)
{
this.listView1.Items.RemoveAt(0);
}
ListViewItem item = new ListViewItem(EmployeeID);
//item.Text = EmployeeID;
item.SubItems.Add(EmployeeName);
item.SubItems.Add(DateTime.Now.ToString());
this.listView1.Items.Add(item);
this.listView1.Refresh();
}
private void myScanner_StatusNotify(object Sender, EventArgs e)
{
// Get ReaderData
Symbol.Barcode.BarcodeStatus TheStatusData = this.myScanner.Reader.GetNextStatus();
switch (TheStatusData.State)
{
case Symbol.Barcode.States.IDLE:
this.statusBar1.Text = "Idle - Scan ID Barcode " + MacAddress + " | " + strIPAddress + " | " + version;
break;
case Symbol.Barcode.States.READY:
this.statusBar1.Text = "Ready - Scan ID Barcode " + MacAddress + " | " + strIPAddress + " | " + version;
break;
case Symbol.Barcode.States.WAITING:
//this.myScanner.StopRead();
//this.myScanner.StartRead(true);
this.statusBar1.Text = "Waiting- Scan ID Barcode " + MacAddress + " | " + strIPAddress + " | " + version;
break;
default:
this.statusBar1.Text = TheStatusData.Text + " " + MacAddress + " | " + strIPAddress + " | " + version;
break;
}
}
private void Form1_OnClosing(object Sender, EventArgs e)
{
if (isReaderInitiated)
{
myScanner.DetachReadNotify();
myScanner.DetachStatusNotify();
myScanner.TermReader();
}
}
private void pictureBox1_Click(object sender, EventArgs e)
{
this.Close();
}
private void pictureBox2_Click(object sender, EventArgs e)
{
this.myScanner.StopRead();
this.myScanner.StartRead(true);
}
}
}
请注意，这仍在进行中，因此缺少一些功能，但我希望在继续之前让扫描仪正常工作。任何帮助将不胜感激，谢谢。