Well to simplify it, whenever I use sendkeys from a background thread it just doesn't work. I even created a textbox, button, and backgroundworker with the following code:
Public Class Form1
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
[Code].....
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
CheckBox1.Checked = True
While CheckBox1.Checked = True
SendKeys("{END}")
End While
End Sub
That is the code, the error is "SendKeys is a type and cannot be used as an expression."
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?
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I'm working with BackgroundWorker, I want the BackgroundWorker do the retrieval process of data from database while the user can still do another task on the form. The problem is, after retrieving the data, I can't seem to access the ListView in my Form from the DoWork event of BackgroundWorker, I will populate that ListView using the data I've retrieved.
Consider this example, this is how I'm doing it:
Public Class Test
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
[Code].....
How do run processes synchronously from a thread or backgroundworker thread? Is it even possible?We have program that allows the user to download several files from a remote server, compress them, and then email the files.It has several long running processes that must run in order. We want these to run on a separate thread so as not to make the form unresponsive. Does a way exist to do this? We attempted a rather clumsy way of approaching this problem by using background worker threads. When each thread is completed and returned back to RunWorkerCompleted, we start another background worker thread and repeat the the next process. It works somewhat but seems to take a lot of resources to run.
View 1 RepliesI'm using vb.net 2005 and trying to get a old vb 6 app upgraded that uses sendKeys. I'm using:
SendKeys.SendWait("%{TAB}")
which should be the proper text for Alt+Tab, anyone else having a similar problem or know of another way to get this to work?
I am using a class with below code, the question is how to update the label's value at UI thread from the backgroundworker?
Imports MySql.Data.MySqlClient
Public Class clsBackGroundWorker
[code]....
im sorry if this has been asked before.but i couldent find it in my first look i have a form that runs a query on a mysql database but as it runs the query the form stops responding till it finishes sooo i had the smart idea of putting it in a back ground worker..
GREAT i thot i had it working it all seemed to go greeat then i noticed when i try to change the label text on the form to corispond to the info it got... it wont work it give me a cross threading error....
how to cross thread between the back ground worker and the origial form..
I wanna sleep a second thread of BackgroundWorker. I tried to use Me.Dispatcher.Thread.Sleep(500) in DoWork event, but it fails.
View 3 RepliesI have some classes right now that I have that I reuse for Client/Server programming. I'm using Thread in these classes though for monitoring for things being written to the network streams and stuff like that. I'm just not sure if I should be using the background worker class instead. I'm also using TCPClient and Listener classes, should I be using sockets directly? I guess it would all depend on the flexibility I would need in a given application's specs.
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So I have a form with a textbox1 thats supposed to enter in a set of keywords and then ebay will give you the"Instant suggestions" in return, but when I have my textbox1.text send the text over to the ebay form, ebay will not return any suggestions, unless I use the sendkeys.send method. Well, I do not like the sendkeys.send method because it's way too buggy &only works under the right conditions.Here's a pic of google instant and ebay does the same thing. So here's what I'm trying to get ebay to do:Here's the code that I have:
Dim theElementCollection As HtmlElementCollection = WebBrowser1.Document.GetElementsByTagName("input")
For Each curElement As HtmlElement In theElementCollection
[code].....
I write a program designed for interacting with an Android phone that is hooked up to a Windows machine. One of the tools in my program is a utility designed to help the user root their phone.Now in order to root it goes through a command line utility called adb which lets you access a terminal on the phone. It must then type commands in that terminal. Most processes that this program does can be done through a batch file, however rooting the phone isn't one of them. The reason being once it actually logs in to the phone's shell, it stops running commands because it just gets stuck on that line, waiting for it to finish. So despite being a little primitive I designed that part of my application to use sendkeys. So the way it should work is:
1) It launches powershell as an adminstrator
2) Types the following commands (I have abbreviated the number of commands it types for the sake of this board. There's actually about 20 lines total): [code]
For the people that have this happen to them, it's always the exact same thing. It's like it completely skips all letters until it gets to a special character. I have no clue what could be causing this. The only thing I have found was that sendkeys wasn't totally supported but that running it as administrator would fix that, which is why I now have it run as admin. But that didn't help. I also had some success by using powershell instead of cmd, but it's still failing for a small number of people.Any ideas what would be causing this? Every other part of the program works perfect except for this. I haven't found any common element between the people that it is failing on. They aren't running the same anti-virus or the same programs. I program and debug on Windows 7 64 bit, yet someone else can run it on the same OS and it won't type it out properly.
I have an application that I want to load using the scheduler in windows. I am also wanting the "enter" key pressed when the app loads. Because you cannot use a batch file I tried using a vb app. It works great on two different windows 7 machines but not at all on the xp machines. The xp machines load the app but don't follow through with the sendkey.
Sidenote - I had to repeat the sendkey function in order to get this to work because I am not sure how to use the sendkeys.sendwait function. I tried and it never worked.
Dim ProcID As Integer
ProcID = Shell("C:Program FilesAdobeFlash Media Live Encoder 3.1FlashMediaLiveEncoder.exe")
[Code].....
Im trying to do this
[Code]...
But it will just skip to the last status (Label3.Text = "Status: Welcome")
I am writing an 'Admin Console' that accesses hMailServer via its provided COM interface. I am using Visual Basic 2010 Express. In one procedure, it scans for the whole accounts. Because it's a lengthy procedure, I shove it into a set of BackgroundWorker threads.
First result: A maximum of 19 simultaneous threads, with 36 seconds total time.Then I rewrote a time consuming thread initialization code segment, and managed to reduce the time required to approximately 14 seconds... but the thread count now hit 330 threads!Will that huge amount of threads be detrimental? E.g., causing out-of-memory exceptions &c. ?
I am using the BackgroundWorker to do the heavy tasks so the UI thread doesn't get blocked. While the BackgroundWorker can send values to the UI thread using the progress-scheme, how can the BackgroundWorker get some values FROM the UI thread?
Either by asking it or simply by the UI thread sending some values to the BackgroundWorker?
Just accessing a variable of the UI thread like UIForm.x within the BackgroundWorker does not work, it does not seem to have access to the UI variables?
I have a background worker that's checking the status of four services on a remote server.This is setup on a timer (5 Seconds) as below. For some reason it's hanging the UI thread causing the application to 'lock' for a second each tick, I cannot work out why?!
Private Sub ServiceTimer_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ServiceTimer.Tick
_ServiceBGWorker = New System.ComponentModel.BackgroundWorker()
[code]......
I'm running some tasks on a BackgroundWorker thread and needed to display the current tasks in a label.Before adding the label, the tasks were completing just fine and the UI was responsive.Once I added the labels, the UI has become unresponsive. The issue, I believe, is the Invoke property.I've declared all my tasks, including the updating, in a sub and am getting the Invoke property of the label each time, in order to set the information.The following is an example of what I'm doing:
VB.NET
Private Sub Test()If lblTask.InvokeRequired = True Then Dim mi As New MethodInvoker(AddressOf Test) lblTask.Invoke(mi)
[code]....
VB 2008 Express. I write a program designed for interacting with an Android phone that is hooked up to a Windows machine. One of the tools in my program is a utility designed to assist the user root their phone. Now in order to root it goes through a command line utility called adb which lets you access a terminal on the phone. It must then type commands in that terminal. Most processes that this program does can be done through a batch file, however rooting the phone isn't one of them. The reason being once it actually logs in to the phone's shell, it stops running commands because it just gets stuck on that line, waiting for it to finish.
So despite being a little primitive I designed that part of my application to use sendkeys. So the way it should work is:
1) It launches powershell as an administrator
2) Types the following commands (I have abbreviated the number of commands it types for the sake of this board. There's actually about 20 lines total):
SendKeys.SendWait("mount -o remount,rw -t yaffs2 /dev/block/mtdblock3 /system{ENTER}")
SendKeys.SendWait("cat /system/bin/sh > /system/bin/su{ENTER}")
SendKeys.SendWait("chmod 4755 /system/bin/su{ENTER}")
SendKeys.SendWait("flash_image recovery /sdcard/recovery-RA-heroc-v1.2.3.img{ENTER}")
Now it seems that for 90% of users, this works perfectly fine. However for a small group of people, this is what actually gets typed in to the powershell window:
> /system/bin/su{ENTER}
_image recovery /sdcard/recovery-RA-heroc-v1.2.3.img{ENTER}
For the people that have this happen to them, it's always the exact same thing. It's like it completely skips all letters until it gets to a special character. I have no clue what could be causing this. The only thing I have found was that sendkeys wasn't totally supported but that running it as administrator would fix that, which is why I now have it run as admin. But that didn't work. I also had some success by using powershell instead of cmd, but it's still failing for a small number of people.
Every other part of the program works perfect except for this. I haven't found any common element between the people that it is failing on. They aren't running the same anti-virus or the same programs. I program and debug on Windows 7 64 bit, yet someone else can run it on the same OS and it won't type it out properly. Is there something better that I could be using instead of sendkeys?
Yes, I see what you mean. But I had to do it that because I tried to do it this way:
CODE:
but its says "Cross-thread operation not valid: Control 'RichTextBox1' accessed from a thread other than the thread it was created on."
What is the difference between creating a thead using BackgroundWorker and creating a thread using System.Threading.Thread?
View 2 Repliesi have lurked on these forums before and finally signed up..i have a situation that, after days of searching the web, i have not been able to come up with a solution for.i have to fire off a function that takes a large amount of time (writes to database, creates files, etc etc)this function is a non-shared function of a class. if need be i could make it Shared.[code]the code works great, but what i need to be able to do is update a form with a progress bar as the job is processing.all of the examples i have seen that do this are being called from within a Windows Form and they access the form directly - i cant do that in this case. my form needs to be 1 form for 1 job being executed - can process multiple jobs at one time and thus i need multiple forms.i have tried making the form part of my delegate class but since it runs in the same thread the effect is it "freezes" until the job is complete.i have just started looking into using a background worker but again, all examples i have seen use the component as part of a form - that wont work for me.
View 3 RepliesI'm trying to add information to a ListView from a BackgroundWorker thread. I thought I could do this in this manner:
vb.net
Private Delegate Sub _ListView(ByVal lvi As ListViewItem)
Public Sub test(ByVal lvi As ListViewItem)
[Code].....
When I attempt to run the "test" sub the BackgroundWorker, I get an error:
Argument not specified for parameter 'lvi' of 'Public Syb test(lvi as System.Windows.Forms.ListViewItem)'.
Is there something I need to specify when declaring the sub, or in the sub itself?
I'm using the following to check the state of checkboxes and then activate some public subs based on the checked state of the checkboxes:
vb.net
Public Sub TestSub() If Me.CheckBox1.InvokeRequired Then Me. CheckBox1.Invoke(New MethodInvoker(AddressOf TestSub)) Else Begin() End If End Sub
Within the Begin sub, I have code that performs specific actions and then updates a ListView with that information.As far as I can tell, the actions are being performed, but the ListView isn't being updated with the info.I'm calling the Test sub from a seperate form, within the BackGroundWorker's DoWork event.Would I have to check the InvokeRequired property of the ListView as well?I'm looking more into the documentation of the BackGroundWorker.
I have an application that interacts with third party COM objects. A method of the COM object that I call will sometimes stop responding. I created a Backgroundworker thread to call the function and I am trying to monitor it from my main thread to kill it if it hangs. I have additional code (not supplied) that tracks the processing time using system.timer from the main thread and I raise an event if it exceeds my threshold (this part is fine). This is when I want to kill the thread and stop code execution. The problem is.. if I use the cancelasync method it will just pend since the code execution is stuck on the function call.
The particular function call in the code snippet that hangs is "objCOM.SendDataToServer()". It typically takes 1-3 seconds to return, but if it gets no response it will just hang indefinitely and won't return at all (no errors just hangs).. there is no timeout... and since I don't have access to the source function I cannot supply one. I tried the .dispose() method of the thread, but apparently that doesn't kill it and neither does cancelasync. I just need help figuring out how to KILL this thread so I can reset the server connection and call the function again.
Public Class COMobject
Private objCOM as new acs.manager
Public Sub CallComFunction()
[code]....
i've been looking for a solutions/alternatives to use sendkeys in Vista after reading many threads about the issue, i did see posts of alternatives, there was mentioning that SendKeys does work in Vista with .Net v3.x Framwork. (thread :"[RESOLVED] cant use the sendkeys function in vista " post # 14 ,with the following link
[Code]...
so before i download and install .Net v3.5 Framework (because the computer i am using is not mine, borrowed it from a freind)i wanted to ask , can anyone confirm that this is true,if i will install .Net v3.5 Framework on windows Vista then the SendKeys command will work as usual (as on windows XP)??p.s. here is a link explaining how to know which version of .Net framework is installed on the computer[URL]..
A winforms dialog is using BackgroundWorker to perform some asynchronous operations with significant success. On occasion, the async process being run by the background worker will need to raise events to the winforms app for user response (a message that asks the user if they wish to cancel), the response of which captured in an CancelEventArgs type of the event.
Being an implementation of threading, I would have expected the RaiseEvent of the worker to fire, and then the worker would continue, hence requiring me to pause the worker until the response is received. Instead however, the worker is held to wait for the code executed by the raise event to complete.
It seems like method I am calling via the event call is actually on the worker thread used by the background worker, and I am surprised, since I expected to see it on the Main Thread which is where the mainform is running. Also surprisingly, there are no cross thread exceptions thrown.
Is it possible to create a WebBrowser control in a background thread in BackgroundWorker?
Private Sub BackgroundWorker1_DoWork(ByVal sender As System.Object, ByVal e As System.ComponentModel.DoWorkEventArgs) Handles BackgroundWorker1.DoWork
Using web1 As New WebBrowser[code].....
Does anyone know a way to create a background WebBrowser? I would like to do it to extract info from websites then spit out the various HTML DOM arrays
I have a form with Check Boxes on it and a second form that holds functions and a Backgroundworker.When a button is pressed on the first form, the second form loads and then runs the functions that relate to the appropriate Check Boxes.Doing it this way causes the second form to become inaccessible. I decided to run my code in the Backgroundworker's DoWork event and then call the RunWorkerAsync method in my form's Activated event. Before using the Backgroundworker, everything worked fine and now it doesn't.I assume the issue is with the Backgroundworker not being able to access controls on another thread.In debug mode,it automatically throws an exception, but doesn't error out when using the Release version, making me assume it's a legal call. But, if it's a legal call, then why can't I access the controls?
View 10 RepliesI have a backgroundworker that is downloading data from different webpages and process them to a datagridview.I get the Cross-thread operation not valid error on the first For loop.
Private Sub BackgroundWorker1_DoWork(ByVal sender As System.Object, ByVal e As System.ComponentModel.DoWorkEventArgs) Handles BackgroundWorker1.DoWork
dim i as integer
tot = (numPostnrTo.Value - numPostnrFrom.Value) / 10
[code]....
