Little proble while scanning barcode !!!

N

naimish_hit

Joined
Jun 22, 2007
Messages
3
Reaction score
0
Hi,
​

​
I am trying to implement barcode functionality on my device (Sumbol MC70), I am using,
​
  • VS 2005​
  • Compact FW 2.0​
  • Symbol SDK 1.5 for .NET​
  • Windows Mobile 5.0 Pocket PC SDK​
I have referred Symbol developers guide and created a device application but its throwing NullReference error on Sysmbol.Barcode.ReaderDAta object creation line !!! I have marked that line with Red color in below code.
​

​
following is my code, Please someone have a look and let me know what I am missing:
​
using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Text;

using System.Windows.Forms;

namespace BarcodeScanning

{

public partial class frmBarcodeScanning : Form

{

private Symbol.Barcode.Reader objReader = null;

private Symbol.Barcode.ReaderData symReaderData = null;

public frmBarcodeScanning()

{

InitializeComponent();

}

private void menuItem1_Click(object sender, EventArgs e)

{

this.Close();

}

private void barcode1_OnStatus11(object sender, EventArgs e)

{

Symbol.Barcode.BarcodeStatus barcodeStatus = objReader.GetNextStatus();

label2.Text += barcodeStatus.Text;

}

private void barcode1_OnRead11( object sender, EventArgs e)

{

System.Windows.Forms.MessageBox.Show(symReaderData.Text, "HelloScan");

this.ReadData();

return;

//try

//{

// switch (symReaderData.Result)

// {

// case Symbol.Results.SUCCESS:

// listBox1.Items.Add("Barcode Device: " + symReaderData.Source.ToString());

// listBox1.Items.Add("Data Read: " + symReaderData.Text.ToString());

// listBox1.Items.Add("------------------");

// this.ReadData();

// break;

// default:

// listBox1.Items.Add("No data was read.");

// listBox1.Items.Add("Status of Read: " + symReaderData.Result.ToString());

// listBox1.Items.Add("------------------");

// break;

// }

//}

//catch (Exception ex)

//{

// listBox1.Items.Add(ex.Message.ToString());

// listBox1.Items.Add("------------------");

//}

}

private bool InitReader()

{

try

{

// Get selected device from user

////Symbol.Generic.Device MyDevice =

//// Symbol.StandardForms.SelectDevice.Select(

//// Symbol.Barcode.Device.Title,

//// Symbol.Barcode.Device.AvailableDevices);

////if (MyDevice == null)

////{

//// MessageBox.Show("No Device Selected", "SelectDevice");

//// return false;

////}

// Create the reader, based on selected device

this.objReader = new Symbol.Barcode.Reader();

////this.objReader = new Symbol.Barcode.Reader(MyDevice);

this.symReaderData =

new Symbol.Barcode.ReaderData

(Symbol.Barcode.ReaderDataTypes.Text, Symbol.Barcode.ReaderDataLengths.DefaultText);

//"at Symbol.Barcode.ReaderParams.SetReaderParams()\r\nat Symbol.Barcode.Actions.Read()\r\nat BarcodeScanning.frmBarcodeScanning.ReadData()\r\nat BarcodeScanning.frmBarcodeScanning.frmBarcodeScanning_Load()\r\nat System.Windows.Forms.Form.OnLoad()\r\nat System.Windows.Forms.Form._SetVisibleNotify()\r\nat System.Windows.Forms.Control.set_Visible()\r\nat System.Windows.Forms.Application.Run()\r\nat BarcodeScanning.Program.Main()\r\n"



////objReader.ReaderParameters.ReaderType = Symbol.Barcode.READER_TYPE.READER_TYPE_LASER;

////objReader.ReaderParameters.ReaderSpecific.ImagerSpecific.AimType = Symbol.Barcode.AIM_TYPE.AIM_TYPE_TRIGGER;

////objReader.Parameters.CodeIdType = Symbol.Barcode.CodeIdTypes.AIM;

//this.symReaderData = (Symbol.Barcode.ReaderData)barcode1.Reader.Actions.NewReaderData();

objReader.ReadNotify += new EventHandler(barcode1_OnRead11);

objReader.StatusNotify += new EventHandler(barcode1_OnStatus11);

//barcode1.ReaderData = this.symReaderData;

objReader.Actions.Enable();

//barcode1.EnableScanner = true;

return true;

}

catch (Exception ex)

{

return false;

}

}

//"at Symbol.Barcode.ReaderParams.SetReaderParams()\r\nat Symbol.Barcode.Actions.Read()\r\nat BarcodeScanning.frmBarcodeScanning.ReadData()\r\nat BarcodeScanning.frmBarcodeScanning.frmBarcodeScanning_Load()\r\nat System.Windows.Forms.Form.OnLoad()\r\nat System.Windows.Forms.Form._SetVisibleNotify()\r\nat System.Windows.Forms.Control.set_Visible()\r\nat System.Windows.Forms.Application.Run()\r\nat BarcodeScanning.Program.Main()\r\n"

private void ReadData()

{

objReader.Actions.Read(this.symReaderData);

//barcode1.Reader.Actions.Read(this.symReaderData);

}

private void cmdRead2_Click(object sender, EventArgs e)

{

//"at Symbol.Barcode.BarcodeMarshal.GetSoftTrigger()\r\nat Symbol.Barcode.Actions.GetSoftTrigger()\r\nat Symbol.Barcode.Info.get_SoftTrigger()\r\nat Symbol.Barcode.Info.set_SoftTrigger()\r\nat Symbol.Barcode.Actions.ToggleSoftTrigger()\r\nat BarcodeScanning.frmBarcodeScanning.cmdRead2_Click()\r\nat System.Windows.Forms.Control.OnClick()\r\nat System.Windows.Forms.Button.OnClick()\r\nat System.Windows.Forms.ButtonBase.WnProc()\r\nat System.Windows.Forms.Control._InternalWnProc()\r\nat Microsoft.AGL.Forms.EVL.EnterMainLoop()\r\nat System.Windows.Forms.Application.Run()\r\nat BarcodeScanning.Program.Main()\r\n"

objReader.Actions.ToggleSoftTrigger();



//barcode1.Reader.Actions.ToggleSoftTrigger();

}

private void cmdRead3_Click(object sender, EventArgs e)

{

//barcode1.Reader.Actions.Flush();

objReader.Actions.Flush();

}

private void frmBarcodeScanning_Load(object sender, EventArgs e)

{

if (this.InitReader())

{

this.ReadData();

}

}

private void label2_ParentChanged(object sender, EventArgs e)

{

}

private void frmBarcodeScanning_Closing(object sender, CancelEventArgs e)

{

objReader.Actions.Flush();

objReader.Actions.Disable();

objReader.Dispose();

symReaderData.Dispose();

return;

}

}

}



Regards,
​

​
Tomy Hanks​

​
 
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