I tried your suggestion. Did not get the exception. But the message
contents did not appear in the buffer. The only way this will appear is
if I use ref or out. But then memory gets corrupted. I am deplying
this to the Windows CE emulator. I have attached the files...
Rodger Higgins
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using System;
using System.Drawing;
using System.Collections;
using System.Windows.Forms;
using System.Data;
using System.Text;
using System.Runtime.InteropServices;
using MessageQueue ;
namespace MessageQueueMarshellExample
{
/// <summary>
/// Summary description for Form1.
/// </summary>
public class XTalkForm : System.Windows.Forms.Form
{
private System.Windows.Forms.TextBox Message;
private System.Windows.Forms.ListBox Received;
private System.Windows.Forms.Button SendBtn;
private System.Windows.Forms.Button Read;
private int hWriteMsgQueue = 0 ;
private int hReadMsgQueue = 0 ;
public XTalkForm()
{
//
// Required for Windows Form Designer support
//
InitializeComponent();
//
// TODO: Add any constructor code after InitializeComponent call
//
MsgQueueOptions mqo = new MsgQueueOptions() ;
mqo.dwSize = Marshal.SizeOf( mqo ) ;
mqo.dwFlags = MsgQueue.MSGQUEUE_ALLOW_BROKEN ;
mqo.dwMaxMessages = 5 ;
mqo.cbMaxMessage = 64 ;
mqo.bReadAccess = false ;
hWriteMsgQueue = MsgQueue.CreateMsgQueue( "Rodger", ref mqo ) ;
if ( hWriteMsgQueue == 0 )
{
MessageBox.Show( "Write Err: " + MsgQueue.GetLastError() ) ;
}
mqo.bReadAccess = true ;
hReadMsgQueue = MsgQueue.CreateMsgQueue( "Rodger", ref mqo ) ;
if ( hReadMsgQueue == 0 )
{
MessageBox.Show( "Read Err: " + MsgQueue.GetLastError() ) ;
}
}
/// <summary>
/// Clean up any resources being used.
/// </summary>
protected override void Dispose( bool disposing )
{
base.Dispose( disposing );
}
#region Windows Form Designer generated code
/// <summary>
/// Required method for Designer support - do not modify
/// the contents of this method with the code editor.
/// </summary>
private void InitializeComponent()
{
this.Message = new System.Windows.Forms.TextBox();
this.SendBtn = new System.Windows.Forms.Button();
this.Received = new System.Windows.Forms.ListBox();
this.Read = new System.Windows.Forms.Button();
//
// Message
//
this.Message.Location = new System.Drawing.Point(8, 7);
this.Message.Size = new System.Drawing.Size(184, 22);
this.Message.Text = "Message Here";
//
// SendBtn
//
this.SendBtn.Location = new System.Drawing.Point(216, 8);
this.SendBtn.Text = "Send";
this.SendBtn.Click += new System.EventHandler(this.SendBtn_Click);
//
// Received
//
this.Received.Location = new System.Drawing.Point(8, 40);
this.Received.Size = new System.Drawing.Size(184, 142);
//
// Read
//
this.Read.Location = new System.Drawing.Point(216, 40);
this.Read.Text = "Read";
this.Read.Click += new System.EventHandler(this.Read_Click);
this.FormBorderStyle = System.Windows.Forms.FormBorderStyle.SizableToolWindow;
//
// XTalkForm
//
this.ClientSize = new System.Drawing.Size(314, 192);
this.Controls.Add(this.Read);
this.Controls.Add(this.Received);
this.Controls.Add(this.SendBtn);
this.Controls.Add(this.Message);
this.Text = "XTalk";
}
#endregion
/// <summary>
/// The main entry point for the application.
/// </summary>
static void Main()
{
Application.Run(new XTalkForm());
}
private void SendBtn_Click(object sender, System.EventArgs e)
{
if ( hWriteMsgQueue != 0 )
{
UnicodeEncoding UEncoder = new UnicodeEncoding() ;
byte[] msg = UEncoder.GetBytes( Message.Text ) ;
if ( !MsgQueue.WriteMsgQueue( hWriteMsgQueue, ref msg, msg.Length, 0, 0 ) )
{
MessageBox.Show( "Err: " + MsgQueue.GetLastError() ) ;
}
}
}
private void Read_Click(object sender, System.EventArgs e)
{
if ( hReadMsgQueue != 0 )
{
byte[] msg = new byte[1024] ;
int len = 0 ;
int flags ;
if ( !MsgQueue.ReadMsgQueue( hReadMsgQueue, out msg, 64, out len, 0, out flags ) )
{
MessageBox.Show( "Err: " + MsgQueue.GetLastError() ) ;
}
else
{
Received.Items.Add( "OK" ) ;
UnicodeEncoding UEncoder = new UnicodeEncoding() ;
string msgString = UEncoder.GetString( msg, 0, msg.Length ) ;
MessageBox.Show( msgString ) ;
}
}
}
}
}
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using System;
using System.Runtime.InteropServices;
namespace MessageQueue
{
/// <summary>
///
/// </summary>
public class MsgQueue
{
public const int MSGQUEUE_NOPRECOMMIT = 0x00000001 ;
public const int MSGQUEUE_ALLOW_BROKEN = 0x00000002 ;
public const int MSGQUEUE_MSGALERT = 0x00000001 ;
public MsgQueue()
{
//
// TODO: Add constructor logic here
//
}
public static int GetLastError()
{
return Marshal.GetLastWin32Error() ;
}
[DllImport("Coredll.dll", SetLastError=true)]
public static extern int CreateMsgQueue(
string lpMsgQueueName,
ref MsgQueueOptions lpOptions ) ;
[DllImport("Coredll.dll", SetLastError=true)]
public static extern bool WriteMsgQueue(
int hMsgQ,
ref byte[] lpBuffer,
int cbDataSize,
int dwTimeout,
int dwFlags ) ;
[DllImport("Coredll.dll", SetLastError=true)]
public static extern bool ReadMsgQueue(
int hMsgQ,
out byte[] lpBuffer,
int cbBufferLen,
out int lpNumberOfBytesRead,
int dwTimeout,
out int dwFlags ) ;
}
public struct MsgQueueOptions
{
public int dwSize ;
public int dwFlags ;
public int dwMaxMessages ;
public int cbMaxMessage ;
public bool bReadAccess ;
}
}
