VS 2008 TCP Listener - Only Responds To 1st Message?
Apr 8, 2009
OK this is my third thread on TCP problems and the first two I managed to figure out for myself within 10 mins of posting before anyone had a chance to reply so lets see if it works again - failing that if you have any advice I'd be most grateful.
I have a server app which should be sitting and listening for messages on one port (4000) and then processing requests and sending data back via another TCP client on a different port (4001). My code is based on someone else's example and it works fine sending and receiving the first message, however after the first message the listener seems to stop listening and never gets any further messages.
Am I misunderstanding how they work? After I get the first message do I need to close the listener and create a new one, or should the same listener keep working until I close it?
[Code]...
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Jan 31, 2012
I am looking to make a SMTP (Port 25) listener to listen in and accept incoming mail, look at the message source, make changes if needed, and retransmit the message out another port. This iwll make it act like a sort-of intermediary service.how one would write a port listener in VB.net, that could listen in on the port, and display the message in a text box (the whole source, headers and all, since that's what the mail comes in as anyway).
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Sep 30, 2009
I'm wondering if it's possible to create a listener type application that would monitor webaddresses that the user attempts to go to. And can then either block or redirect the browser to another website. Purpose: I know this seems to sound a little weird but what I'm attempting to do is a NetNanny type application that can run on the user's PC and the allow, prevent, rewrite (would look for particular keywords and rewrite them "words I wouldn't want my 7yr old seeing or reading), or redirect to other webpages. I would also like to be able to handle both IE and Firefox browser with this one application.
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Feb 25, 2012
iam working in a project autocomplete in comboboxes respond's too slow ,but there is a form have too many control's on it when i remve it autocomplete working fine ,but i can't Dispense this form.
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Oct 1, 2008
My Application contains a button and two text boxes. 1st textbox is for user input known as tbHost.Text 2nd textbox is for displaying results after button is clicked, this is set to readonly. The button is a start button that will call a new process every time it is clicked. I intend to let user to have a choice to either click on button to display result or press enter key to display result.
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Sep 8, 2009
I am having trouble with XMLTextWriter.WriteStartElement throwing an exception:
System.InvalidOperationException
when trying to write the second element in my XML document. This error comes back as "The Writer is closed". I have not closed it, so I am guessing it has fallen out of scope?? I have created a class to write an XML file using XMLTextWriter as an object within my class. Below is the relevant code. I have found one other post on codeguru that was never answered with the exact same issue.
Function CreateXML()...
Try
_listDocument = New XmlTextWriter(_xmlDI.FullName & "\" & currentFilename, Nothing)
CreateHeader()
[code].....
I am calling these functions after instantiating a dimension from ListXML (the name of my class) with the following code:
Dim xmloutput As New ListXML
xmloutput.CreateXML()
xmloutput.AddListMember(xmloutput.ReturnWhiteList, currentItem.SenderEmailAddress, xmloutput.ReturnAddAction)
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Dec 4, 2009
I'm working with a disconnected dataset that is NOT using a database. I'm maintaining an external file in xml format using the ReadXML and WriteXML methods of the dataset. I have a Holiday table structure in the dataset with the following columns:
-HolidayDate
-HolidayName
When the app starts I read the Holidays into the dataset. I then check the Holiday table to see if any of the Holidays are in the past. If so, I want to delete the given Holiday row from the Holiday datatable. I'm running the following code: [code] If the HolidayDate is in the past it calls the Delete method ok but when it tries to execute the Next statement it raises an InvalidOperationException exception with the message "Collection was modified; enumeration operation might not execute".
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Jan 16, 2011
i have one project in which i am using listbox as display to let user know what software is doing internaly, this include i/o opration.The problem is listbox is late when the operation is fnished then it respond,s
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Mar 11, 2010
The goal -- use VB.Net to write a windows forms application that responds to a limited set of voice commands after the user says a keyword, (such as "Wake Up"). I have the following code I am using from another site but I am getting an error I do not understand (nor do several others who posted comments at the same site.)
Imports System
Imports System.Data
Imports System.Deployment
[Code].....
If I had any understanding of how to create a grammer file I MIGHT be able to avoid this error completely, since I am only interested in a few voice commands (maybe 30), not the whole 60,000 word dictionary.
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Nov 14, 2011
I'm writing an add on to an existing program through an API, but the event I need doesn't exist. How do i go about creating my own event in VB.
I'm writing a plug-in for a program called promis-e that works in conjunction with Microstation CAD platform to generate electrical drawings.I need to call a function I wrote when a new symbol is added to the active drawing, but that event isn't available in promise, so I was wondering if I could write my own event in Microstation that calls that function ?
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Nov 1, 2009
How to add winsock listener in Vb 2008
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Jan 16, 2010
I'm having a hard time getting the fundamentals down about these TCP Socket classes.
When you use TcpClient, you can set the IP Address or domain name to connect to the server end of the socket. I see examples that use "localhost" as the first parameter for TcpClient. Is this just a broadcast over the network to find the server that has a TcpListener listening on the dictated port of the second parameter of the TcpClient declaration? With any IP address for TcpClient (I realize that's an option, though), how does "localhost" find the TcpListener server?
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Jan 4, 2010
create a http listener using vb .net.
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Jan 22, 2012
When I stop my TCP Listener by the Stop command, I always get an error because I use BeginAcceptTcpClient to accept the clients. How can I stop a listener properly?
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Dec 2, 2009
(Using vb 2008 express.)
I am trying to create a server to send clients text on request. I am using a tcp listener to accept clients then send each client to a thread in a threadpool which deals with each client's request then closes the client connection. It seems to work fine but I would like to know how it works. Using the listen loop below I cant help feeling I should be sending some values to the threaded sub. How does it know which client each thread is dealing with?
Sub ListenLoop()
Looop:
Client = Server.AcceptTcpClient
[Code].....
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Apr 27, 2009
is there a way to use my tcpclient and listener to use a no-ip host because i am on a laptop
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Dec 16, 2010
I am trying to write a program that has a server/listener program and then 2 client programs, the 2 client programs are supposed to be able to chat with each other. Can anyone point me in the right direction on this?
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Aug 23, 2011
I'm another newbie with VB (2010) so please bear with me. I am attempting to make a method that is event driven by data threads on the Ethernet port. Simply put, the method is to wait until a data thread from a "Control By Web" 5-input device sends an "information update" data packet to the application, with the application then processing the information. This application is on a private, well controlled network, with no access to the internet. I have a method that is working right now reading data packets when invoked with a timer (see code below) but I really need it to be event driven.
' this is added at the top of the class
Dim tcplistener As New TcpListener(IPAddress.Any, ip_port)
'this is added in the "form1_load" module
[code]....
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May 1, 2012
I am trying to build a small window component, which has two buttons.
When I click on the Start button, my code needs to establish the connection to server and keep checking the status (this is infinite loop, I have a boolean global variable which is set to true and based on this loop will work).
When I click on stop button, it should stop checking (I will make global variable to false).
I have code to check my server status.
However, since it is kind of infinite loop, moment i click on start, window form is not taking any other actions, since the control not coming out of event listener of start button.
I have many scenarios like this kind of infinite loops.
How to resolve this, what kind of approch should i follow in vb.
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Jan 30, 2009
I have an SMTP listener that accepts incoming connections and routes the message to a folder using FileStream. I have to add x-sender: email@address.com and x-receiver: email@address.com to the first two lines of the file so it can be put in a pickup folder for relay later. It seems as though this way of handling the incoming stream is corrupting the HTML in the email message body. Does anyone have a clue what I am doing wrong or a suggestion that would point me in the right direction regarding what I am missing?
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Jul 7, 2011
I intend to write a .NET application that does logging and analytics to data using VS 2010. I want to link my application with an external non .NET application via intranet. This external application provides integration through URL triggers. When an event occurs it can send this event parameters to any application via HTTP/HTTPS POST or GET requests. It allows me to select the event parameters to be included in the HTTP request that will be sent as URL parameters. URL parameters consist of a name and a value, and are separated from the URL with a question mark (?).
So an example request can look like this: [URL] any dynamic elements in the URL are displayed in brackets (<>), and are replaced by the corresponding event used at run time.
Now what design method should I follow to create a component in my application to listen to the URL request and parse it's elements. Knowing that I want to protect my URL listener with a username and password.
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Oct 9, 2009
I am using vb2008. I am creating a port listener. When I test the listener I get an exception in the code as shown below.I send one record through ("Hello") . When it tries to read again I get the error. This read would result in EOF. When this happens, shouldn't i go to 0? Instead it keeps its previous value of 5 which is the number of characters in "Hello"
m_blnStop = False
Dim server As TcpListener
server = Nothing
Try
[code]....
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Dec 23, 2011
I create a small program witch is a tcp client.I sent a asqii string to a tcp device over ethernet thads acts like a server.As soon as the device recieves the input string it will respond back with response data. The problem is i am not getting any response data back from the divice. The lenght of the string is max. 30 characters.When a use WireShark i see the reponse, but VB read nothing.I have read many threads with explenations about server/client connections but no example of a client with a tcp listener built in.I think thad the stream read is to late after the send instruction.
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Jan 30, 2009
I am totally new to socket connections, so I've pieced together code from the internet to try and start a TCP Listener object. [code] Is it possible to create a TCP listener that does not need a specific number of connections initialized? Can I just have it listen on an open port until data is received? I will be receiving a lot of data at once from many servers...
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Jun 13, 2009
I hava a MDI app. i have a mdiChlid(say A) and others n instances of another mdichild. i wanto to this others n instances can handle an event generate in the A mdi chlid. How ca i do this??
[Code]...
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Sep 18, 2010
I am just try to convert C# statement into Vb.net that is comm.MessageReceived -= new MessageReceivedEventHandler(comm_MessageReceived);
Reference: GSMCommunication.dll
Where MessageReceived is an Event and comm_MessageReceived is a sub function which need to AddressOf with that event i try this one to
RaiseEvent comm.MessageReceived += New MessageReceivedEventHandler(AddressOf comm_MessageReceived) but intelligence responds "End of statement expected"
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Jan 22, 2010
but is there some way to create a program that would be able to listen to internet radio and possibly display live artist/song info from several stations on a windows form? Has anybody done anything like this or have any ideas as to how to tackle this?
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Dec 9, 2009
Im trying to make a basic client and listener chat room but im having problems with method invoker.
Error: Error1Method 'Private Sub CliInfo(CliMess As String)' does not have a signature compatible with delegate 'Delegate Sub MethodInvoker()'
Imports System.Net.Sockets
Imports System.Threading
Imports System.Text[code]......
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Jan 6, 2010
create a message box that stores my user name, message, and post datetime into the database as messages are sent. Soon came to realise, what if the user changed his name? So I decided to use the user id (icn) to identify the message poster instead. However, my chunk of codes keep giving me the same error. Says that there are no rows in the dataset.
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
Dim name As String
Dim icn As String
Dim message As String
[code]....
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Feb 22, 2009
how to create an error message by message box to tell the user to enter a number only if they key in a character value?
I MEAN AFTER THEY PRESS THE CALCULATE BUTTON
Private Sub btnCalcFat_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnCalcFat.Click
Dim intFat As Integer
intFat = Integer.Parse(txtFat.Text)
lblResultDisplay.Text = txtFat.Text * 9
End Sub
My text box is call txtFat
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