I am using the BeginConnect method of a socket to connect to a server which may or may not be on line I need to provide my users with a countdown timer which they can abort the attempted connection if they wish to The question is; how can I interrupt the Begin Connect method of an asyncronous connection
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Microsoft's System.io.file.exists and System.io.directory.exists can take FOREVER, especially if you're in a situation, where you've unplugged from the network and you're looking in a share.
So, to get around this, I've created a thread that times out after 3 seconds. Returning false, if the calls above haven't yet returned. To do this, my main thread passes its instance to the new thread and immediately calls:
Thread.Sleep(TimeOutInSeconds * 1000) ' Where TimeOUtInSeconds = 3
The new thread then goes and checks for the file / folder using the System.io.file.exists / System.io.directory.exists functions.
Regardless of the result, then it uses the main thread's reference to call Thread.Interrupt().
My main thread doesn't get interrupted. It stays there for the full 3 seconds. If I were to change that to 3 minutes ( and I have ), it'll sleep for 3 minutes.
Consider a MyForm class that contains a shadowed implementation of Show(). It also contains a CreateForm() method, which accepts an instance of the form and calls the shadowed sub:
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While using the Socket.Receive method to receive messages through network, you should define a variable as the buffer and you have to specify the length like this: Code: Dim _ReadBuffer As Byte() = New Byte(LENGTH) {} My question is: What is the bad thing about increasing the length of this variable even if the received messages are sometimes shorter? (i.e. if some body let it 10000).
View 1 RepliesI'm writing a program for a testing environment. Where there is the Teacher's workstation and 30+ Student workstations.This is my first time writing a networking application so this is all new. It's also not totally in my job description either, but that's another topic.
What I'm looking at is using BeginConnect as the connecting command from the server to the client. I'm not looking for a chat program which seems to be the only thing I see for server/client coding and it's not very helpful. I only want the Clients to be listening for the server. I figured I'll be using the [System.Net.Sockets] namespace. But I'm just so unfamiliar with it and nothing seems to break it down, explaining what each thing is looking for. Mostly just been sifting through sample code and trying to draw my own conclusions...unsuccessfully I might add.
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I will try to explain what I need.Let's say that I have a class like this:
Public Class Example1 Public Sub ToBeCalled()
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I am using a RichTextBox control and a Socket Class. When I use the AppendText function in Form_load it get's added, but not in the event when text is received.
Code:
Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
client.Connect(URL, PORT)
RichTextBox1.AppendText("Connecting...")
End Sub
Private Sub client_onConnect() Handles client.onConnect
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Just so you know, the MessageBox showing in Data is working perfectly.
I wrote a server for a tcp/ip chat program using the system.net.sockets class. When I run the program and the client tries to connect to it, there's an error and it won't work. I am positive that the issue isn't with the client, as I have made a connection with the client before.
Imports System.Net
Imports System.Net.Sockets
Imports System.IO
Public Class Form1
Dim server As New TcpListener(IPAddress.Any, 60)
Dim client As New TcpClient
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I am in the process of prototyping a small sockets application, which monitors IT infrastructure (due to in-house financial and deployment restrictions, I am unable to utilise an existing commercial or open-source solution). Basically, I have a server application and associated agent process for communicating heart-beat data to the server. The server application implements a TCP socket class (TCPDevice), which is called from a WinForm. I am aware of the restriction on updating the UI from processes running on separate threads, and that the preferred technique for acheiving this is via the use of Delegates in conjunction with the Invoke method. Having had very little need previously for using Delegates (apart from of course std windows events and the BackGroundWorker control), I am at a loss as to how to do this in the context of my application, and would appreciate some assistance, although it has occurred to me that I could use the backgroundworker for marshalling updates to the UI.
Eventually the application will need to update a grid of devices via feeds from the defined agents, however for the purpose of this exercise simply updating a status bar on the UI will suffice. The section of the code which I believe is relevant to propogating the code to the form is contained in the OnDataReceived method.Below is a code excerpt from the protoype app which should put the above into appropriate context:
Code from the form:
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I've been creating short test apps repeatedly to try to understand some of the concepts in VB.NET.For the most part it has been illuminating.I read Bucky's .NET knowlegebase tutorial on passing objects as parameters to newly created forms. He shows how to create a new class that inherits from the base form class and define a New() method with parameters Extending the concept I thought about doing the same thing with a form that was created at design-time (In this case Form2).
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Base class has one field to hold numeric balance value. With 2 methods that accept arguments for adding and subtracting the new input calculating new balance. Sub class has four fields dates, transaction, memo and amount.I have a deposit form, and withdraw form. Each time one transaction is entered it creates an object with sub class fields, then adds to the account collection. My problem is not understanding how to call the deposit/withdraw method and pass the current transaction amount back to the base class to alculate the new balance. Does anyone have any links to information/tutorials on how to perform something like this? As you can see with my code I have tried various different approaches without any success.
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I'm writing a GUI-based app in VB.net that talks to a LambdaMOO server via telnet, sends commands to display the object hierarchy, then parses the output and creates a visual representation of the object hierarchy.So my question is: is there some kind of "telnet client" class for .NET to simplify the sending and receiving of data, or do I have to write my own using the socket API?
View 7 RepliesSupose a base class
Public Class airplane
Private var_num_seats As Integer
Private var_num_engines As Integer
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Obviously, I don't wish that the class Glider has the method "start_engines" neither the property "num_engines". Otherwise, other child classes may have. How can I supress these property and method in child class, not just ignoring (if I can)?
class
eg: dim classobj = xyz("CLASS_NAME") ' where classname is a valid class name
and dynamically raising a known method of that class on that newly created object or class reference.
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I am trying to create a socket class in my project to send data to ecr (electronic cash register).Ecr comes with software that listens for commands on port 3535. Command are in forms of XML Files. It has only one catch, I must close the connection on socket, so the ecr would know when to process the command and respond. Since I only send one command at a time,I need the simplest solution I can get.
How it works:I create the socket and connect it to 192.168.1.67:3535 I start
client.BeginReceive
Then I send the command with
client.BeginSend
And I do a
client.Disconnect(True)
so I can get response from ECR.And in 8 of 10 times it works just fine. The problem is this few times it doesn't work.At that time I cant receive anything because it reports that the client is not connected in ReceiveCallback but it still manages to send the data to ECR just fine. The bill comes out on the ECR, but I get no answer about what happened.
I call the class like this:
Dim dre As New HCPSocket
Result2 = dre.Otkucaj(Command1, "192.168.1.67")
Debug.Print(Result2)
dre = Nothing
End the class looks like this:
Imports System
Imports System.Net
Imports System.Net.Sockets
[code]....
I'm trying to update an application from vb6 to vb.net. The orig app used the winsock control. Unfortunately I can't nor do I want to use it in the re-write. Are there any decent public classes with events that wrap the Socket class?
View 1 RepliesI am indifferent if you are a VB.NET or C# or other .NET developer. I have a FACTORY class like the following:
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I'm writing a set of unit tests for a large, complex class called ImageEditor from a piece of legacy code, where image processing and GUI functionality isn't strictly divided. One of the methods in the class, BaseImageChanged, seems to be concerned entirely with how images get displayed and should be disabled in my unit tests to avoid unnecessary complexity. The test project is in C#, and the original code is in VB; my idea was to create a Decorator for the class in C# and then hide the method behind an empty one that does nothing. However, when I try running the unit test, the VB code keeps referencing the old BaseImageChanged method as though the replacement didn't exist. Here's what I'm doing:
(VB class)
Public Class ImageEditor
...
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I wrote a Socket Client which will send the Socket Server some data and get some response from Server. This process will be running once in every 2 seconds.
Now what I need to know is How we can identify the connection lost between Server and Client?
I need this to be implemented in the Client side. If there is no connection then Client should automatically close the connection. Once the connection with the server is available in the next attempt it should connect automatically.
I'm trying to code a class of RandomNumber. One of the class methods needs to populate a "List (Of RandomNumber)" ... which was passed as a parameter to the method ... with 10 random numbers between 1 and 50. DEAD SIMPLE :)
View 6 RepliesI have written a application that searches the users computer for all files within a specified folder.Sometimes the number of files can be quite large. I would like the user to able to interrupt (end) this process.My code is handled by a button click in a VB win form.[code]I have tried various MsgBoxes that warn the user but I think a Esc Key or a Cancel button would be better.
View 8 RepliesI'm using a long string using SAPI speech and I want to be able stop the speech rather than have to listen to it babble on throughout the whole thing. So, in one function, we'll say it's the load function, it declares a speech string: [Code] I'm trying to get it to abort reading the audio but can't seem to figure out how to get it working. I've seen examples that have used SVSFlagsAsync and SVSFPurgeBefore Speak but I can't get either to be recognized and I've added (what I believe to be) the necessary resources to the library and added the imports at the top of the page. Does anyone know how to interrupt the speech?
View 1 RepliesI know this is possible, and it is probably something simple that I am missing... I have a fairly complex class to handle deserialization of an XML file. I wish to place a [class].loadfile method within the class. It looks something like this: Serialization decoration left out for simplicity...
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The Deserialization is working just fine (that's my own code), but assigning the object value to Me is not correct. What I want is for an instantiation of this class to have a LoadFile method (similar to the XML class LoadFile method) - but I cannot figure out how to set the value of the class from within the class.
I have an event I want to do continuously until a button interrupt is pressed.
Here's the pseudo
Click button 1:
Check if button 2 is pressed
If not, do stuff
If so, stop doing stuff
End routine
So what I currently have is this:
Dim randominteger As Integer = 0
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles StartSampleButton.Click
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Unfortunately, it's never breaking outside of the first loop. How to get around it?
May i know how to fire an event using the serial port interrupt method in visual basic windows form? Currently, now i am using the polling method which is using the timer event to continuously poll the port every 1sec.
But now i would like to change to the interrupt method which will fire up the same event without using the timer event.
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A spreadsheet formatter that I made for the department opens and closes Excel spreadsheets in the backround. If someone opens Excel while the macro is running, it stalls the entire program. I need a way to sense Excel opening, then stop it, preferably with a message box saying what just happened.
View 1 RepliesBelow is my code, but when i send the message thru client socket i receive Specified argument was out of the range of valid values. Parameter name: size
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim serverStream As NetworkStream = clientSocket.GetStream()
Dim outStream As Byte() = _
System.Text.Encoding.ASCII.GetBytes("0800822000000000000004000000000000000920092126012345001")
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How to simplify this, 2 method in class are identical.First class.
Public Class Gui
Inherits System.Web.UI.Page
Public Sub CreateStyleLink(ByVal StyleArray() As String)
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I am getting an error when trying to call a form from within a method:
Expression is not a method
My code structure looks like this:
Public Class frmMain
Class Server
Private Shared Sub StringMessageReceived()
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How can I call the windows form within the class?
How to simplify this, 2 method in class are identical.[code]
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