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因此，我写了一个快速的示例程序，以更好地了解Janam扫描枪，但我遇到的问题，我从来没有见过，虽然我相信可能是由于在不同的线程和传递值之间他们。所以我不相信我正确使用委托。和帮助，将不胜感激。C＃移动扫描仪值奇怪
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using Scanner;
namespace ScannerTest
{
public partial class Form1 : Form
{
//Delegates
private delegate void RefreshValuesDelegate();
private delegate void AddScannedItemDelegate(Item item);
// SINGLETON //////////////////////////////////////
private static Form1 instance = null;
public static Form1 GetInstance()
{
if (instance == null)
instance = new Form1();
return instance;
}
///////////////////////////////////////////////////
public Form1()
{
InitializeComponent();
}
void Form1_Load(object sender, EventArgs e)
{
/**************/
//SCANNER ACTIVATE
GlobalScanner.GetInstance().Close();
GlobalScanner.GetInstance().BarcodeDelegateDirector = new GlobalScanner.BarcodeDelegate(Form1.GetInstance().processScannedBarcode);
GlobalScanner.GetInstance().Open();
/**************/
}
// Add the new part unless the part number contains
// spaces. In that case cancel the add.
private void button1_Click(object sender, EventArgs e)
{
if (textBox1.Text.Equals("") || textBox2.Text.Equals(""))
{
MessageBox.Show("item names or barcodes cannot be blank.");
}
else
{
Item temp = new Item(textBox1.Text, textBox2.Text, DateTime.Now);
if (temp.ItemCheck == true)
{
AddToList(temp);
}
}
}
public void processScannedBarcode(string scannedBarcode)
{
if (scannedBarcode != null && scannedBarcode.Length > 0) // 0 = SUCCESS Symbol.Results.SUCCESS
{
Item temp = new Item();
temp.ItemName = "N/A";
temp.BarcodeNumber = scannedBarcode;
String tempDate = DateTime.Now.ToShortDateString();
String tempTime = DateTime.Now.ToShortTimeString();
temp.ScanDate = tempDate + tempTime;
AddScannedItem(temp);
}
}
private void AddScannedItem(Item item)
{
if (this.InvokeRequired == true)
{
this.Invoke(new AddScannedItemDelegate(AddScannedItem), new object[] { item });
}
else
{
this.textBox2.Text = item.BarcodeNumber;
this.textBox1.Text = item.ItemName; // description not available
item.ScanDate = DateTime.Now.ToLongDateString();
//DateTime readDate = DateTime.Now;
//cargo.SetReadDate(readDate);
RefreshValues();
AddToList(item);
}
}
private void AddToList(Item item)
{
string tempItem = item.ItemName;
string tempBarcode = item.BarcodeNumber;
string tempDate = item.ScanDate;
ListViewItem newRow = new ListViewItem(tempItem);
newRow.SubItems.Add(tempBarcode);
newRow.SubItems.Add(tempDate);
listView1.Items.Add(newRow);
RefreshValues();
//MessageBox.Show(string.Format("TextBox1: {0} TextBox2: {1}", tempItem, tempBarcode));
textBox2.Text = "";
textBox1.Text = "";
}
public void RefreshValues()
{
if (this.InvokeRequired == true)
{
this.Invoke(new RefreshValuesDelegate(RefreshValues));
}
else
{
listView1.Refresh();
}
}
}
// A simple business object for example purposes.
public class Item
{
private string name;
private string number;
private string date;
private bool check = true;
public Item() { }
public Item(string nameForItem, string numberForBarcode, DateTime scandate)
{
ItemName = nameForItem;
BarcodeNumber = numberForBarcode;
date = scandate.ToShortDateString();
}
public string ItemName
{
get
{
return name;
}
set
{
if (value.Length <= 45)
{
name = value;
}
else
{
MessageBox.Show("Item name to long. Must be less than 45 characters.");
ItemCheck = false;
}
}
}
public string BarcodeNumber
{
get
{
return number;
}
set
{
if (value.Length <= 20)
{
number = value;
}
else
{
MessageBox.Show("Barcode is to long. Must be less than 20 digits.");
ItemCheck = false;
}
}
}
public string ScanDate
{
get
{
return date;
}
set
{
date = value;
}
}
public bool ItemCheck
{
get
{
return check;
}
set
{
check = value;
}
}
}
}
因此，手动输入数值可正常工作，但扫描仪被激活并读入数值。调试器会显示正确的值，并在代码通过列表时进行设置和存储，但是屏幕不会显示任何内容，也不会像手动输入时那样将值保存到列表视图中。
就像我之前说过的，我认为它是一个代理和扫描程序线程将值传递给主线程的问题，它只是不喜欢。
感谢您的帮助提前。
以下为手动键入在视图值 
这里是正在使用扫描仪的图。我没有评论该消息框，所以你可以看到它正在收拾东西。 
答到某人的问题： 
这里是为那些想一探究竟全球扫描仪。
using System;
using System.Linq;
using System.Collections.Generic;
using System.Text;
namespace Scanner
{
public class GlobalScanner
{
#region About using the delegate in this class
/* We are actually using one central class to do the scanning, but user can scan from different screens.
* If we don't have a delegate we will have the following scenario. We scan the barcode, the barcode will be
* captured in our scanner implementation class "For example: IntermecBarcodeScanner" and we will have no way to return
* the barcode back to the scanning screen. The delegate will actually help us to do that job. The delegate will
* be associated with a method inside the scanning form. It will carry the scanned barcode over to that method
* inside the scanning form.
*
* We need 3 main things to get the delegate working:
* 1- Declare a delegate variable
public delegate void BarcodeDelegate(string barcode);
* 2- Initialize a delegate and associate it with the appropropriate method in the scanning form:
* Example: GlobalScanner.GetInstance().BarcodeDelegateDirector = new GlobalScanner.BarcodeDelegate(this.ScanBarcodeEvent);
* We need the above line of code to be in the scanning form. That's how we associate the ScanBarcodeEvent() method
* with the delegate that is in the GlobalScanner class.
* 3- In GlobalScanner class we created two variables to help us to connect to the scanner implementation class such as
* the IntermecBarcodeScanner. Those two variables are: barcodeDelegateInstance and barcodeData
*/
#endregion
//Declare a delegate
public delegate void BarcodeDelegate(string barcode);
private IBarcodeScanner scanner = null;
// SINGLETON //////////////////////////////////////
private static GlobalScanner instance = null;
public static GlobalScanner GetInstance()
{
if (instance == null)
{
instance = new GlobalScanner();
}
return instance;
}
// ////////////////////////////////////////////////
private BarcodeDelegate barcodeDelegateInstance = null;
//BarcodeDelegateDirector will be accessed to associate the method
//that's in the scanning form with the delegate
public BarcodeDelegate BarcodeDelegateDirector
{
get { return barcodeDelegateInstance; }
set { barcodeDelegateInstance = value; }
}
//We also created this variable to set the barcode value from other classes such as IntermecBarcodeScanner
private string barcodeData;
public string BarcodeData
{
get { return barcodeData; }
set
{
barcodeData = value;
barcodeDelegateInstance(barcodeData); //barcodeData is the scanned barcode and it comes from the GlobalScanner implementation
}
}
public void Open()
{
String deviceName = Platform.GetOEMInfo();
if (deviceName != null)
{
if (scanner == null)
{
if (deviceName.Equals(Global.INTERMEC_DEVICE_1) || deviceName.Equals(Global.INTERMEC_DEVICE_2) || deviceName.Equals(Global.INTERMEC_DEVICE_3))
scanner = new IntermecBarcodeScanner();
else if (deviceName.Equals(Global.JANAM_DEVICE_1) || deviceName.Equals(Global.JANAM_DEVICE_2) || deviceName.Equals(Global.JANAM_DEVICE_3))
scanner = new JanamXMBarcodeScanner();
else if (deviceName.Equals(Global.JANAM_XG_DEVICE_1) || deviceName.Equals(Global.JANAM_XG_DEVICE_2) || deviceName.Equals(Global.JANAM_XG_DEVICE_3))
scanner = new JanamXGBarcodeScanner();
else if (deviceName.Equals(Global.MOTOROLA_DEVICE_1) || deviceName.Equals(Global.MOTOROLA_DEVICE_2) || deviceName.Equals(Global.MOTOROLA_DEVICE_3))
scanner = new MotorolaBarcodeScanner();
}
scanner.Open();
}
}
public void Close()
{
if (scanner != null)
{
scanner.Close();
}
}
}
}
这也使用在移动窗口视觉工作室2008年5.0 –
你知道同步原语？Mutex，WaitHandles等？如果你有竞争条件，你必须保护两个线程可以同时处理数据的区域 请参阅'System.Threading'-命名空间。 除此之外，你能告诉可能会出现竞争条件的部分？ –
不，我目前不知道关于synchronization0primitives或mutex的信息，但是我明白你的意思，我相信我的AddToList函数是他们可以访问的唯一地方bly重叠但我不确定。 –