Update A Textbox With New Text From Another Class On Another Thread
Apr 16, 2011
im still stuck and i really to get past this and move onto the rest of my program. I'm trying to update a textbox with new text from another class on another thread. I can get this to work no problem on another thread with the same class, and on the same thread in another class. but not on another thread on another class. my code looks like this, when it is run to produces no errors but does not add the test to the text box, what is wierd is i had made some changes to the program to add multiplelines to consolebox.text and then checked console.text from form2 and it produces the values i added but those arent reflected inside in the consolebox for some reason.
I am having trouble accessing the main thread (my form) when calling thread is running in a class (or module). I have no problem to manipulate a data (in a thread) from a form, the textbox can be updated using delegate and invokerequired but it doesn't seem as easy when the thread that processes a variable is handled by a thread that is running in a class.
Updating the TextBox from a Thread that calls a function within a Class does not work. I'm trying to get this to work in a DLL (but I tried without as well). The DLL is accepting an Object as an argument[code]....
Form1.vb Imports System.ComponentModel<br/><br/>Public Class Form1 Public Delegate Sub updatePB(ByVal value As Integer) Private bgworker As BackgroundWorker = New BackgroundWorker
I created a new thread to run with a loop to update a textbox (this is just a demo, in reality this thing would go out to a db every x minutes to request an update). I did this on a timer, but i wanted to try to do it on a different thread.. anyways, this is what I have: (one form, one textbox, and this code...)[code]I'm getting a warning through (the "Thread.CurrentThread.Sleep(2000) part is underlined) which states:"Access of Shared Member, Constent Member, enum Member, or Nested Type through an instance; qualifying expression will not be evaluated".
I have a textbox which will accept a user input for a email address or phone number.I want to using a new thread do a search for various results and populate a listbox.I know i need to do this in another thread so my main form will still operate but how can I do this? I've never used threads before and I know it's tricky to get the values from a textbox and also update a list box on another thread.
im trying to access a richtextbox from another class and thread then the ui and i cant seem to get it working. I currently have the sub thats handling the the work inside of a public class and its a sharedsub, im going to be calling it from several different classes and threads but again i cant seem to get it working. the code looks like this. Public Class SharedSubs
[code]...
i would be calling sub using SharedSubs.Console("stringstring") when this is called from the ui thread it works fine but when its called from anyother thread or class its does nothing,ive confirmed it going thru this code but its not displaying anything in the textbox and its not thru an exception due to delegates either which i figured it would.
I have a TCP server app that starts 2 threads when the server is activated, I want the threads to add text to the textbox on the main form. Here's is what I have tried [code]I have added MsgBoxes at points so I know the Sub updatetext_ is being called, and the text is being passed, they are also showing that InvokeRequired is always FALSE. In any case the textbox txtMessages is not being updated.
I run a thread from my main form that do some stuff i want that each action that the thread do will be written on a lable on the main form. How can i do that? I try to give it a pointer of the form but with no luck since its not allowed by the compiler. here is how i create the thread object in my form:
I tried to update the button text on a form from a backgroundworker.do_work event, and it failed, with the usual cross-thread exception message.However, by pure chance, I also tried to update text in a system.windows.form.toolstripstatuslabel also from this backgroundworker.do_work event, and it DOES work. Question: why is this? Is it perhaps because theres some kind of implicit shared behaviour with system.windows.form.toolstripstatuslabel?
A BackgroundWorker thread can pass data to the primary thread. It does it via the RunWorkerCompleted and ProgressChanged events, which I believe run in the primary thread. I would like to encapsulate the BackgroundWorker control in a class so that I can instantiate it more than once. But I don't know how the BGW can then communicate with the primary thread. If the BGW control is within a class, it does not have access to the properties outside the class. In that case, how can the BGW pass data to the thread that instantiated it?
I have a program that runs for some time and I would like to update the user on its progress. The rest of the GUI is updated using Delegates and Invokes and such (Java is Soooo much cleaner in this regard - everything is thread safe!!), but there is no invoke method for the progress bar. How can I use a delegate to update the progress bar when there is no invoke to invoke!!
I have a function called textupdate that updates text1.text value. when i call this function in Form1_Load, text1 is updated successfully. However, when i call this function in Private Shared Sub function2, no update is done. I am a newbie in vb.net programming and it may be a silly question but I could not solve it
I want it to update the selected item in the list box with the text from different text boxes and 2 combo boxes. The text of the selected item is split by "|" in different text and combo boxes.
I have a simple vb.net app and I'm trying to update a one row Access table with data from some textboxes. This is a learning exercise for me as I am coming back from not programming for almost 10 years, and know there are lots of other ways to manage this data, but I'm just trying to understand different aspects of ADO.net a little better.
The ERROR I'm trapping is:
"Syntax error in UPDATE Statement"
Any thought's as to what is going on? (See CODE and stuff below)
Here's the Scheme printed from ACCESS showing the exact spelling of the database table and column names:
I've created a private sub called addIRCRoom Which makes the Tab and the TextBox, but i can't figure out how to update the text in the TextBox.I've made this function to handle it:
Private Sub displayOut(ByVal Channel As Object, Optional ByVal User As String = "", _ Optional ByVal Message As String = "") Channel.Text = "<" & User & "> " & Message & vbCrLf End Sub
But i just get this error all the time: "Public member 'Text' on type 'String' not found."how to update the text
I'm creating a Client Server application which involves theServer running some scripts in clients and getting back results in an automated way. In Server, other than Main thread, i have 2 worker threads, a) one monitoring response from clients and b) the other scheduling next available job to respective client which executes that job. The issue here is ,I want these worker threads to write the status of their work in the UI(which comes under Main Thread). Also i need to write things in worker thread in a Data table and Rich Text Box in Main thread. But, I can't do so, since it has been blocked to access one thread's function or property directly from others. Is there any work around to do this?
This is my first post on this forum, so please excuse me if I'm posting wrong. Anyway, I've been having an issue that I've never seen before and is driving me nut, I have a windows form on which I have placed many textboxes that display information from a MS SQL database. The user can then change these values and hit a "save" button which writes the changes to the database. I also have certain textboxes that with the "on leave" event (after a user enters a possible new value) trigger a method that recalculates some of the other fields based on the new information. Hopefully that all makes sense.
So the problem is, when I run through this "recalc" method the first time around, it doesn't update those textboxes that it's supposed to. However, when I put a breakpoint in and debug through it, the debugger shows it putting in the correct values into the textboxes. It's just as soon as the method is done, it puts them back to blank, or whatever they were before
'Rebind stuff here lblCabinets.Text = curMfg.ToString("c") txtCabinets.Text = curMfg.ToString("c")
in the richtextbox(from my class) gotfocus -what I need is the richtextbox.text to also be in a different textbox on the form. the richtextbox(readonly) is from my class that has mousedown and mouseup code and more than one richtextbox (small in size) will be on the form in a container so when user clicks on one I need the richtextbox.text to also be in a regular textbox (not from my class) and not located in container. And I need to read a property I made in my richtextbox class.
Im working on a program ( vb 2005 CE framework ). I have mainly two threads, the main one and another one I use it for a different thing.When I tried to update the UI this exception was thrown : Control.Invoke must be used to interact with controls created on a separate thread.well !I have tried to use the INVOKE, but it wouldn't work. this is where I get the error :
Public Sub PaintKeys() Dim tempLevel As clsLevel Dim tempKey As ClsKey
The usual VB way to handle a computationally heavy task is to put it in a background worker thread, while the main thread keeps handling the UI.Say for whatever reason I needed to do this the other way around: the main thread doing the grunt work and the background one updating the UI.Here's what I have so far. The only problem is, while the UI window (Form1) does get redrawn, you can't interact with it, not even move or resize it (the mouse cursor turns to hourglass and won't click).
Public Class ProgressDisplay Private trd As Thread Public Sub New() trd = New Thread(AddressOf threadtask)
[code]....
The client will call it like this (actually in unmanaged c++ over COM but you get the picture):
Dim prog = new ProgressDisplay() DoLotsOfWork(addressof prog.update) ' DoLotsOfWork method takes a callback argument to keep client informed of progress
below is a small part of my asynchronous TCP connection code. When I connect I'm passing a ListViewItem as Object parameter. I'd like to update the ListViewItem once the connection has been established or an error occurs. ServerConnect runs on a separate thread, because it's an asynchronous connection, so I can't update the ListViewItem directly.
Does anybody know how to update the ListViewItem?
I looked at jmcilhinney's asynchronous TCP example in the Codebank forum, but it confused me. I don't know which parts I need and which parts I don't need.
::edit::
One more thing. I also need to update the ListViewItem in the Read sub, but I'm passing "buffer" as Object, so how would I update the ListViewItem there?
vb.net Imports System.Net.Sockets Public Class TCP Private Socket As TcpClient
I am trying to write an app that in the thread will do some tasks, the form lokks like this:and what it should is something like this:
- retrieve data, populate a row in the listview, increase the first progress bar - retrieve data, populate a row in the listview, increase the first progress bar - retrieve data, populate a row in the listview, increase the first progress bar
Basic function - enter 5-10 urls. Download all web pages using multi threads and then process it. Then in the end, the text from all threads should end up in a richtextbox. It can't be done using any of my googly searches so i thought about asking this :
how would you update text in a richtextbox from a different thread?
I am being able to download and process web pages. But can't add it to richtextbox.
I've looked at the on line doc over and over, and I can't seem to figure out why this won't work. This code runs the thread, and the thread seems to execute the code in the 'threadsafe' sub, however neither the progress bar is updated or the button click performed.
Imports System.Threading Public Class VisNotify Inherits Form
I'm not sure exactly how to describe this. In VB6, there was a Timer command. I could create a variable of type Timer and loop until the current value for Timer exceeded the initial plus a given amount of time. This allowed me to update form variables while the timing loop was executing. How can I do something similar in .NET?[code]...
