Basicly I want to create a server that can read data sent by multiply clients and give feedback to them I have found some tutorials before but its only oneway trafic (Client>>>>Server) and the server crashes as soon as the client is disconnected
ps. If its a tutorial with VB it will be nice other visual codes are also good
Actually I have created a chat application is it possible to send data to particular client only?
View 1 RepliesHow to make clients on sql server i mean when i will install my application on clients how i will connect it with sql server?
View 6 RepliesI created application database by vb.net and sql server 2005 now I have some computer on the one of them I installed sqlserver 2005 and other (Clients) computers I installed Application how I can connecting my application to sql server on the pc1 or how I can using connection string.
View 2 RepliesHow to make clients on sql server i mean when i will install my application on clients how i will connect it with sql server?
View 3 Repliesi want to designe a simple program that have one server and multiple clients.i program with vb.net,but dont know anything about winsock, can you send me a sample code for start.
View 1 RepliesI've got a game I would like to build, it will require a central game server where peoples data (game data :-)) will be sent to and shared with other players - how is the done. Is it remoting? TCP? something else - I need to study up on it but want to make sure I'm learning the right thing.
View 3 RepliesI'm new to network programming and i'm trying to write a server that can communicate with multiple clients through tcp/ip, the clients need to communicate with the server to and with the other clients. Currently i've got a client server program that works fine for only one client:
[Code]...
I'll guess to accept multiple clients i have to create some clienthandler class at server side, but i have no idea which code it has to contain, i've already spend hours searching on google but didn't find anything usefull. Can somebody help me with this ?
I am facing a problem in VB .net Client/Server application where I am successfully able to talk between them using TCPListener and TCPClient class usage. However, when I try to connect another Client to the same server on the same welcome port, it errors out throwing an exception or behaves very unexpectedly.Isn't it true that the Server connection is on a WELCOME PORT for all the clients, and that each client connected gets a new port to carry on its communication with the server AUTOMATICALLY (according to the Tomcat webserver working)
View 2 RepliesI made a simple chat system that connects to a server with a client one on one. I'm not really sure how to get multiple clients with the server so that you can see everyone's messages. Here is the source code. The Server only accepts one client at a time.
View 3 RepliesI was just wondering if it's possible to create an app that interacts with a database hosted on a web server... or is it only possible using VB.NET? Also if it is possible, is there any good documentation or tutorials I could reference?
View 2 RepliesI am developing project on cyber cafe using vb .net 2005 and winsock i don't know how to accept connections from multiple clients to a server having winsock control
View 2 RepliesI have 2 clients connected via a server program.When 1 client hits an arrow key, a picturebox moves on client1 and on client2.Before adding this network functionality, the picturebox on client1 moved fast with each click.Now, there is a delay of like 2-3 seconds.I know the code isn't optimal, but i'm not a networking wizard.What i'm doing is when pressing a key on client 1, it passes a text to a textbox in client 2 which then has the picturebox move in client 2 depending on the text.The slowdown occurs on client 1, which is odd because the picturebox isn't directly connected to the network code.[code]
View 3 RepliesI'm trying to get a single field back from the data. (I am searching by a primary key so I should get 0 or 1 answer). Please help. The table that I am querying has one entry with user = someone, input to several columns with the ans column having "a good answer"
Code:
Dim reader As SqlDataReader
Dim par As SqlParameter
Dim result As String
[Code]...
how i read data from Sql server and write that in .csv file with vb.net , after that saving the .csv file with my own name and path? what must i do? for information data in sql like this one:
[Code]....
how to work with XML.I need to create an multilingual application and need to save the controls captions in sql table with xml data typei started the following:[code]I know this is not very professional but thats all i did until know in SQLNow i have a problem in VB.NET i don't know how to read an xml data type (How to get the value from variables).If somebody can give me an exmaple how to read the xml than i would continue translating for each objects in the form where name is like the variable "btnLogin" and give it the controls.text property to the variables value.
View 5 RepliesI need to solve the following problem:- Create a server application which generates a random number every second- Have any number of client applications access the current random number through a dll (associated to the server) at anytime How would I do this? Anyone has a prototype VB.Net code for the server which does this kind of thing? I'm pretty sure I know how to write the client code.
View 5 RepliesI am trying to read JSON data from a server to a dataset object, any idea on how this can be done. I have tried using the DataContractJsonSerializer class but it only seems to work for objects.
JSON Data
{
"firstName": "John",
"lastName": "Smith",
[code]....
The code above works to an object, but I want to parse the JSON data to a dataset object.
I know how to select items from an array with LINQ, but what I can't figure out how to do is access a database using an IQueryable. I connected the database to my project, added two classes from the database to the "LINQ to SQL" .dbml file and saved it. In my programming assignment, I am not supposed to create a data source (table thing) to display the data, but update my own interface manually. In order to do it, I was told to instantiate this:
Private dogs As System.Linq.IQueryable(Of Dog)
(Dog is a class that I added to my .dbml file from the database file)Also, I am told it involves using a method
.AsEnumerable.ElementAt(index As Integer)
I am working on a client/server application. Everything seems to go well for a while (a few hrs, a few mins its kind of random) then suddenly clients stop receiving data. maybe 1 or two, or all of them. in the end I end up having to restart the server piece to resolve it, but I am trying to understand why its doing this. I've added try catches around the send piece, but it doesnt error out. When the app fires, the listener is started on its own thread. When a new connection is made, that connection is passed to a class that handles all of my connection data(send/receive, responding to commands, etc). The class is started in its own thread, so each connection is running in its own memory space. This issue seems to happen with 1 client connected, or 20, it doesn't really seem to matter.
This causes other issues, like a customer who thinks he is disconnected, will shut down his app, which is supposed to send a command to close the connection on the server side which it does not., so now I have several "closed" connections still open on the server, which is obviously also bad. Another thing I dont get is that it worked fine when I was developing the pieces on my dev box, so I dont get why I have all of these "timeout" issues now. (I put that in quotes, because the timeout period is the default of 10 mins, and I xmit data, at LEAST every minute when the server pushes data updates to all clients)
Here is some of the relevant code
vb
'Command Object, this holds all of the command information being passed back and forth to tell the server what to do, and as well as hold the response.
'The strCMD is the command, strParms is the parameters of the command, obj is ANY object I want to send along with this information
<Serializable()> Public Structure CommandData
Public strCMD As String
[Code] .....
Connection succesfuly made (TCPClients) Writing/Reading with NetworkStream At an interval of 16 ms. Client sends 4 bytes -> Server receives 0 bytes ??? Server Sends 4 bytes -> client receives 0 bytes ???
[Code]...
I am just starting out and my boss has this project that I have to do. I have been searching but haven't found anything that can explain well for me to understand. Here is my project. I have 2 xls files that I need to read in. I need to create 2 new xls files from the read in data. Then add columns to each and write in data for those columns.
View 5 RepliesI have a large class that I built to act as a TCP server for one of my silverlight applications. When a user connects it stores the tcp client into a table for later communication. The problem is that when I send data, with more than one client connected, it loops through both open TCP Clients but some how sends the data twice to the same client.... the other tcp client never receives his data. This isn't a logic issue as I can step through the code and see that it is clearly taking each individual TCP client out of the table and sending it the data. They all use the same port... could that be the issue? And if so how do I make it so that it can connect on one port then transfer to another? I have tried using different computers for connecting but still the most recently connected client receives all of the packets of data.
View 6 RepliesI have been struggling to find a solution for this problem. What I need to do is build a server application that accepts tcp client requests from different clients running on same port say:1003. I experimented by using asynchronous mode call backs etc. but it disconnects once connection is established and does not respond for further requests from the same client.
View 1 RepliesI have Visual Basic 2010 Express and SQL Server 2008 R2 (not Express) installed on my Windows 7 machine. In Visual Studio, I am attempting to create a Data Connection to a database in SQL server. Server Mgmt Studio is not running. When I attempt to add a connection in Database Explorer, to the AdventureWorks _Data database, I get the message "This file is in use. Enter an new name or close the file that's open in another program." There are no programs running except VB, except maybe for the SQL Server engine running the background.Please note that I can open and access tables within a database in code
within Visual Studio, I just can't add a connection in Database Explorer.Am I doing something wrong? I've been very frustrated on this issue for a long time
I am wanting to pull data out a select table and wanting to use it locally as Read Only data I am stuck on how to write the data to the local Temporary table[code]...
View 1 RepliesI'm creating a reporting web page as part of a standard VB.NET web application. The page is data driven, with jquery making calls to a web service local to the application to get values of elements that are dynamically created in the DOM. Ultimately these dynamic elements and their values are all wrapped up in a JSON object, so that part of the client side is fine.
Right now, I can pass that JSON object to a method in the web service which creates an SQL Data adapter from the values and queries a database. My ultimate goal is to have this client JSON data be used to query the database and construct an excel file to send back to the user, or failing that a CSV file.
It's my understanding (from working with PDF file generation) that this type of function can only be done on the server side of the web application, not even from the web service (i.e. I can't have the web service return an array of bytes and have JavaScript/jQuery present that as a file).
So, how do I go about this? Now I have my JSON object on the client side, where should I be sending it, how, and how do I go about returning my file?
I've read about either storing the JSON in a hidden field and having the server take the elements value and go from there, or using AJAX to send the JSON to the server just before a postback is made to fire off the server-side function to run the query and return the data.
I just need a little guidance, and a little help understanding where to use the hidden field, or what I am actually doing with the pre-postback AJAX call.
I need to read the email from the mail server that is in my intranet from my application server.
View 9 RepliesI am designing a fairly small application to manage a waiting area for a clinical department. There will be a receptionist who books appointments and updates exisiting appointments to say that a patient has "Arrived". In seperate rooms will be nurses who call patients who have "Arrived" and update the appointment as "In Session" and finally as "Discharged". The appointments are viewed in a flexgrid with nurses across the top and time down the left, patient names are displayed at the relevant times and the cells are shaded a colour to represent the current appointment status ("Booked", "Arrived", "In Session" and "Discharged").
I am using SQL Server as the back-end and Visual Basic 6 (I know) as my front-end.I have been told that there will be 2 or 3 nurses plus the receptionist logged in to the system but I would like to cater for growth.My question is what is the best mechanism to use in order to reflect the status change made by one user on the screens of the other users currently logged in?
I have been thinking about using a timer to refresh the data at a set interval but I do not want to keep hitting the server excessively (although what is considered excessive? we would be talking about a call for data every 60 secs per user). Plus the server could be serving data for many other applications so this is another consideration.Alternatively I have been thinking about sending some kind of message via Winsock to the other users notifying them of data changes as they happen. I don't have a lot of experience with this and am concerned about clients not receiving messages and users seeing old data. It also seems strange to me that once the days appointments have been retrieved from the database that "in theory" a client could go the whole day without having to query the database again to pick up changes - kind of scary.Some information on the data:We would probably be looking at around 100 appointments per day We capture patient name, date of birth, date and time of appointment and appointment status.What is the standard approach / best practice for this kind of scenario?
I am developing a program where i will download and save an xml file from a url as abc.xml. I open the abc.xml in a datagridview with a dataset without problem.I am confused how can i read raw per raw the datagridview and assign the data in a database table? i am using vb 2008 + msde2005 express.I show the whole content of the xml file in the datagridview with the following [code]I dont know how to create a loop where i can read the datagridview line by line save data in variables (ex.strings) and save it in a databese table?
View 6 Replies