threading in diffirent class?? I get an example like this
Public Class Form1
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim NewThread As New Thread(AddressOf Counter3)
[code]....
a thread at example above was written in one class, now how to make a same thing like that with a different class?? and one more thing if you click the button twice then it have two proses.
using multi-threading in my application.Basically what i am trying to do from within a form event is initiate a class instance and then run a function of that class (via a thread) that changes certain member values of that class.Those class member values are then used to update values on the main form.Ive created a simple example below but i cant seem to get it to work.The class values are not updating and im struggling to understand how this threading works.
Class FormMain
Private Sub BtnClick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles myformbtn.Click()
Dim myFileCounter As New FileCounter()
[code]....
Is BindingSource class makes use of Threading to read and write the values in controls and in objects?I mean how bindingsource know when properties of an object changes and sometimes seems not to know? Does it use a kind of BackGroundWorker running to watch changes on bindings objects? And why does it sometimes read and write properties so many times the same value on the same object's property?I found that it's sometimes easier not to use them since it's hard to know why a control do not update but, on the other hand, dealing with control events can be tedious. And what if i tried to make my own BindingSource Class not inherited from the System.Form.BindingSource
View 2 RepliesIn frmMain:
Private Sub DBReadAccountInfo(ByVal strAccountID As String)
Dim tmpaccountInfo As New PublicFunctions.clsAccountInfo
tmpAccountInfo.strAccountID = strAccountID
Dim ReadAccountInfo_Thread As New Thread(AddressOf tmpAccountInfo.DBLookupAccount)
ReadAccountInfo_Thread.IsBackground = True
[code]....
In "sub UpdateAccount", frmMain.InvokeRequired is always false. There's a MenuStrip control I'd like to update the .Text on.
I have created a class for Socket reads so I can create sockets on command. Due to performing a socket read, the program will freeze waiting for incoming data due to being on a single thread. So I created a separate thread for the reading of the sock and attempt to invoke an event to prevent multi-threading errors.
But I am getting an error when trying to Invoke: "Invoke or BeginInvoke cannot be called on a control until the window handle has been created."
How can I fix this or is there a better way to read a sock without freezing the thread?
Class for Sockets:
Option Explicit On
Option Strict On
Imports System.Text
[CODE]...
Calling form code example:
Private WithEvents Socks As clsSock
Private Sub Sock_Connected(ByVal state As String) Handles Socks.Connected
MsgBox("Connected - " & state)
[CODE]...
I'm attempting to communicate via USB to a hardware device. So far I can use CreateFile, ReadFile and WriteFile to communicate with the device efficiently, but occasionally the WriteFile call will hang because there is no device located at the port where it was installed. I have the WriteFile and ReadFile calls in a managed thread that I use the Join() method on to return control to the parent thread.
View 17 RepliesWhat is the best way to access a value of a control within a form outside of the form class. I have a lot of functions defined in a module, one of these functions requires a series of values from controls in my main form such as the FolderBrowserDialog.SelectedPath element. I understand that these cannot be accessed in the format form.FolderBrowserDialog1.SelectedPath and that they need to be accessed using a delegate. This is the part I am stuck with.
[Code]...
If Class X is within the scope of Class Y, is X a subclass of Y?If Class A is a sub Class of B, then is Class B considered a super class of A?if Class C inherits Class D is Class D a superclass or parent of Class C?if Class E extends Class F then we can consider Class E a child of F?if Class G inherits Class H and is within the scope of Class I then who is the parent of Class G? Classes that inherits Class J and classes that are within Class J are all sub classes of Class J?
View 1 RepliesI have put this code in the global form Inherits System.Windows.Forms.Form. And then in the form that will inherit this from the global Inherits MenuStrip. "MenuStrip" is what the global form is called. But keep getting this error: Error1Base class 'MenuStrip' specified for class 'Lesson2' cannot be different from the base class 'System.Windows.Forms.Form' of one of its other partial types.
View 5 RepliesI have a class (see below)
Imports Microsoft.VisualBasic
Imports System.Data.SqlClient
Public Class ClientProfile
#Region "Variables"
[CODE]...
It is in the file ClientProfile I have placed in both App_Code and also App_Code/Models
In my code behind I have the following
[CODE]...
The last word, "ClientProfile" has the scary squiggly red line below it. It is not recognizing my class.Even the Intellisense is not picking up te class. Do I have to register the class file in any way?
I am trying to send emails on a button click ...but I want to send the emails in the background as the number of emails are too many...so I am using threading.
[Code]...
Dim a as Type=GetType(className) would gimme the type. But I have only the name of the class as string. I want something like GetType("class1") which would return the type.
View 2 RepliesI have a program that I would like to implement using Threading.I wand to load a form that takes a couple of minutes to open using threading.Here is my code
Imports System.Threading
Public Class frmAdjustments
Function LaunchForm() As Integer[code].....
I am new to .net programming and could use any suggestions you may have. I'm trying to grasp the concept of multithreading apps and would like to have both my main form (Adjustments) and the (frmNewAdjustments) form to load concurrently.Here is the error I receive with the code above: Overload resolution failed because no accessible 'New' can be called with these arguments:
i'm trying to do a database search in my WPF program. And to give the program some speed, I want to use Backgroundworker or Threading. The problem is that i have to invoke the controls that the new thread is going it access. But i don't know to do this and i don't know i which event to put the code. Here is some code:
[Code]...
I need to be able to call a C++ dll that takes a long time (possibly infinte, it relies on user input)to execute. Im calling this through VB. My VB GUI freezes up when this happens, and I would like to keep the GUI responsive, so that the user can stop this possibly infinte loop. A bit of background, the C++ is trying to keep score on a snooker table using a webcam, and while the VB scoreboard updates easily, I would like to script it so that the analysis is almost continuous, while still allowing the user to interact. Currently the project requires the user to press a button to start the shot analysis, but it would be preferable if the program scripted itself. I have only realised this problem now and the deadline is very soon.
Update: Our lecturer suggested an option to solve the problem, but it would appear that most options here and the one he suggested will not work for us as the processing time required for the webcam image capture is too great to handle due to hardware constraints.
I have the following code. My program loads 20 pictures in one panel and each pictures has for the moment like 500 Kb, but in the future they shall have like 2~6 Mb.When I use this part of code, my program that uses only 6 Mb of memory, but jumpes at 202 Mb when pics are loaded. I need a method to resize or make them thumbnail or something to reduce the memory.I don't know for the moment how to use the System.Threading, but I want to know if it shall help my program, if not, then help me replace parts of my code.Private Sub PanelPictures(ByVal picsoriz As Integer) ' picoriz represents how many pictures should the panel have on each row (it's set at 5 pictures per line/row) [code]
View 4 RepliesI have a program that I would like to implement using Threading. I wand to load a form that takes a couple of minutes to open using threading.
[Code]...
SMS Multi Threading
View 4 RepliesI have a VSTO application, rendering a word documement. At each stage of the rendering a popup window is getting displayed. What we have done is displayed a popup window, and at each stage of the rendering the text is made Changed. I need to display the window using multithreading. How to achieve this.
View 1 RepliesI'm trying to understand how to handle db connections in a multi-theaded windows program.It I have this simple class:
public class MyClass
private myConn as new sqlconnection
private MyThreadPool(5) as Thread
[code]....
I have an app that the user selects a database and the user tables are displayed in a listbox. The user selects which tables to export to an Excel workbook, one for each table. There is a richtextbox that informs the user when the created files are done.
The app works and the xlsx file are created as expected. The problem is when each is finished only the last file of the selected tables is displayed in the RTB.
The form has the following Handler
[code....]
The threading is done in the following
[code...]
how the threading within vb actually works. am i of the understanding that every time you create an event, through a button control for instance, that this infact creates a seperate process which will run independantly to another. say for instance you had two buttons on a form and each contained code which took 5 seconds to execute. if i were to click one button into action and then the other with a second, would the two processes run alongside one another or would i have to wait for the first code to execute before the second button could be executed?
View 13 RepliesI am communicating with a USB-HID device. It will successfully complete hundreds of send-receive requests but occasionally get a Null Exception error.
[Code]...
at the rxData.dataPacket(i) = element I will get a NullReference error every now and then. I could enclose it in a try/catch statement, but I'd like to fix the root problem if possible.This device is communicating to microcontrollers, and it is possible that they won't always give a value... but my feeling is this is some sort of UI threading issue. When debugging, even though there is a null exception, many times there actually does seem to be data in dataReceived.data.ToList(). Is there an easy way to place the whole data processing routine on a thread separate from the UI?Edit: Changed code to match answer and give more info on where it is used. Still get NullReferenceExceptions after about 1,000 completed send/receive requests to the HID device.
I have a problem. I'm creating a new thread, which should do some stuff and update a text box. But, when I test my program, the main (UI) thread is doing all the job, even though I declared and started a new thread.
[Code]...
I even made another thread for testing purposes, but it was the same.
I'm developing an adding for office powerpoint application.I'm trying to display a description of the object(Customized object) currently dropped on the powerpoint slide in design mode(Design mode of the powerpoint).When i click on my addin the related object description will be displayed on a tabbed window as the first tabpage.
There is a button on the tab page, and when i click on it i need the description to get copied to windows clipboard.I tried this using clipboardclass it throws the following exception, System.Threading.ThreadstateException {"Current thread must be set to single thread apartment (STA) mode before OLE calls can be made. Ensure that your Main function has STAThreadAttribute marked on it."}
Code for clipboard:
Clipboard.Clear()
Clipboard.SetText(lblObjectID.Text)
I searched the net for a solution and got couple of answers like, Put [STAThread] in the main function Thread.CurrentThread.SetApartmentState(ApartmentState.STA) Immediately before your call to SetDataObject.
But I'm not sure where to put the 1st one and the 2nd option didn't work.
I'm using vb.net 2005, I've got the following code running a thread to download a file. However, the process fails sometimes when trying to read the local copy of the file. I think I may need to unlock the local file somehow but I'm not sure how to do this.[code]
View 1 RepliesI know .Net and C# pretty well, but never even looked at VB.My problem is: our Win32 COM library is used by a number of clients, and we see that the number of failures is higher for those who use the library from VB (both VB and VB.NET) than for those who use C++, C# or Delphi. One thing about our library is that it is supposed to be used from one thread only - can some threading magic by VB be the cause of failures?
Clients tell us the do not create any extra threads on their own.
I'm creating a password hash recovery tool that uses brute force. I have the brute force algorithm run in a background worker. It all works, but some similar apps I tried out have performance ~100x bigger then my app. (mine does 50k keys/second, some others do 5m keys/second or more.)I realize this is partly caused by using a .Net language, but I suspect there are ways to significantly speed up the brute force. A lot of ppl say I should use multi threading, but how is this done in practice? Splitting up the passwords to check would slow down my app I think.
View 1 RepliesI have a button click event and inside I do a lot of work. While I am doing this work (not from the UI project) I want to send messages to the UI to display to the user.
[Code]...
and inside DoMyWork which is in another assembly i can call SendMessage which writes to the textbox. The messages will only display though when DoMyWork is complete. How can I update TextBox1.Text on the fly without putting DoMyWork on a BackGround thread or do i have to put it on a BackGround thread? I do actually want to block the user from doing anything while DoMyWork is running
I know there are many cases when it's best to multi thread an application but when is it best to multi thread a .net web Application?
View 5 Replies