Hi. (apologies if the cross posting isn't appropriate)
I seem to have a problem with the lifetime of a variable when used with the
thread pool and msmq (I wouldn't know how to replicate the behaviour without
msmq sorry)
This is the error I get when my application calls BeginPeek - Receive -
QueueWorkerItem - BeginPeek within the ide running under debug. The queue
is public and on another machine.
An unhandled exception of type 'System.NullReferenceException' ocurred in
Unknown Module
Additional Information - object reference not set to an instance of an
object.
First of all I place 2000 messages in the queue 124/126 bytes in length a
simple string. Then I start my receive program that does the following -
private MessageQueue mq = new MessageQueue();
private void ProcessWorkRequest(object data) {
string adj = (string)data;
FileStream fs = new FileStream( @"C:\Msmqrec" +
Thread.CurrentThread.GetHashCode().ToString() + " .txt", FileMode.Create,
FileAccess.Write);
StreamWriter sw = new StreamWriter(fs,
System.Text.Encoding.ASCII );
sw.Write(adj);
sw.Flush();
fs.Close();
}
private void OnCommandComplete( object sender,
PeekCompletedEventArgs async ) {
MessageQueue mq = (MessageQueue)sender;
System.Messaging.Message msg = mq.EndPeek(
async.AsyncResult );
mq.Receive();
string adj = (string)msg.Body;
ThreadPool.QueueUserWorkItem( new WaitCallback(
ProcessWorkRequest ), adj );
mq.BeginPeek();
}
private void button1_Click(object sender, System.EventArgs
e) {
mq = new MessageQueue(
@"Mortimus\deliveryrequests");
mq.Formatter = new XmlMessageFormatter( new Type[] {
typeof( string ) } );
mq.PeekCompleted += new PeekCompletedEventHandler(
OnCommandComplete );
mq.BeginPeek();
}
Running the application I get the error at spurious times never the same
amount of messages processed.
If you'd like the source mail me offline.
Robert Rolls.
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