Learn InvokeRequired And BeginInvoke?
Sep 5, 2010where is the best place to learn InvokeRequired and BeginInvoke.
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Begininvoke And Invokerequired Usage?
Dec 1, 2011instead of using if control.invoke required in a procedure can I just call the procedure with begininvoke?I have, possibly, the following:
Private Sub UpDateTimer_Elapsed(sender As Object, e As System.Timers.ElapsedEventArgs) Handles UpDateTimer.Elapsed
UpdateTime()
If MicActive Then
PTTCancelTime += 1
[code]....
Add InvokeRequired / BeginInvoke(Delegate) To Avoid 'Control'
Jun 27, 2011I have a (legacy) form where I had to add the InvokeRequired/BeginInvoke(Delegate) to avoid the "Control control name accessed from a thread other than the thread it was created on." exception.This seems to work fine but there are some scenarios where the BeginInvoke is not calling the Delegate (which I can tell from the output log). [code]
View 1 RepliesInvokeRequired Not Working?
Feb 6, 2011This code works fine in VB 2008 attempting to redo the program in vb2010:
in the GuiForm:
the following is declared in formgui:
Private Delegate Sub UpDateGSLDelegate(ByVal rpn As Integer)
Also the following sub is also in formgui:
Public Sub updateGSLDisplay(ByVal rpn As Integer)[code]....
"UpdateGSL", in turn, will be called from any subs running in another module in a separate thread.The purpose is to update one or more labels on formgui based on the "rpn" variable.now the program will just hang at " Invoke(New UpDateGSLDelegate(AddressOf UpDateTheGSL), rpn)" in the "updateGSLDisplay" sub. no error messages, just stops.also I'm now using the " Dim t1 As Task = Task.Factory.StartNew(Sub()" way to starting a new thread in case that is revelant.what has changed from 2008 to 2010 to cause this. Just started trying out vb 2010? How can I fix this in 2010?
I looked at this page: http:[url]...aspx but it doesn't say anything or maybe it does and I just didn't pickup on it.
Me.InvokeRequired In A Module?
Jun 28, 2010I am using the under given code in a module and I am getting an error ['Me' is not valid within a Module]
[code]...
VS 2008 ListView InvokeRequired?
Dec 9, 2009I had a question about some logic of the InvokeRequired with a ListView. I have the following
vb.net
Public Sub ListviewSub If ListView.InvokeRequired = True Then Dim t As New MethodInvoker(AddressOf ListViewSub) picCurrent.Invoke(t) Else RunSub() End IfEnd Sub
[Code]...
Me.control.InvokeRequired Property Means?
Aug 25, 2009Me.datagridview.InvokeRequired property means in vb.netadil
View 3 RepliesVS 2010 InvokeRequired, But Invoke Not Working?
Feb 3, 2012I read Accessing Controls from Worker Threads and implemented this
Private Sub myExplorer_Close() Handles myExplorer.Close
If Me.InvokeRequired Then
Me.Invoke(New MethodInvoker(AddressOf myExplorer_Close))
[code].....
InvokeRequired Keeps Returning False When True Is Expected?
May 24, 2012I have the following test code. It does nothing useful, but it's there for me to understand VB:
Imports System
Imports System.IO
Imports System.Diagnostics
[code].....
InvokeRequired Returns False When UpdateLabel Function Is Called From A Different Class?
May 10, 2012I am working with tasks, so I've got the following code to update a label on my form:
Private Delegate Sub UpdateLabelDelegate(ByVal s As String)
Public Sub UpdateLabel(ByVal s As String)
If Me.InvokeRequired Then
Me.BeginInvoke(New UpdateLabelDelegate(AddressOf UpdateLabel), New Object() {s})
Return
BeginInvoke Using A Function?
Oct 22, 2010This sub works fine:
Private Sub UpdateInfo(ByVal text As String, ByVal timeStamp As DateTime)
If Me.lstStatus.Dispatcher.Thread Is System.Threading.Thread.CurrentThread Then
' Do stuff with
[code].....
Use BeginInvoke To Ensure That A Second?
May 20, 2009I am having a small 'head banging' experience working on one of our DLL products.The problem I am having is that this application is an outlook addin, and as such, does not own its own Message Pump. No problems there, I have a UI class, which starts a thread, and calls Application.Run(new fControlForm)
I use the Application.Run passing a form, rather than an ApplicationContext purely because I want this form to be in charge of displaying other forms: ie, I can use BeginInvoke to ensure that a second, and many more forms are created in the context of the thread that owns the Message Pump.
I however feel this to be quite hackish. I get a form displayed at startup (which I am sure I can hide if I needed to)My question: IS there any way to create some form of Invoke procedure in an applicationContext that uses the Message Pump thread? I have created a class which implements the ISynchronizeInvoke and can Invoke from a thread that it owns, however this is not the same as invoking from the Message Pump owner.
Calling BeginInvoke On Another Thread?
Jul 25, 2011So from the comments section where this persons code was translated to VB.NET on [URL]it shows a little code to aid in calling cross thread UI stuff.
<System.Runtime.CompilerServices.Extension()> _
Public Function SafeInvoke(Of T As ISynchronizeInvoke, TResult)(ByRef isi As T, ByRef [call] As Func(Of T, TResult)) As TResult
[Code]....
Error 1 Data type(s) of the type parameter(s) in extension method 'Public Function SafeInvoke(Of TResult)(ByRef call As System.Func(Of frmLogin, TResult)) As TResult' defined in 'GvE.Globals' cannot be inferred from these arguments. Specifying the data type(s) explicitly might correct this error. C:GvEGvEfrmLogin.vb 37 9 GvE
I'm calling that code from inside a method defined in a form but that method is being called from another thread.
Just trying to avoid delegates and this is what the code above is supposed to do, but just can't get it to work.
Where Can Found Begininvoke Documentation
Mar 1, 2011I simply want to find documentation about invoke and begininvoke. A member of delegates. simply searching on it on bing and stuff don't show anything. It shows control.invoke, etc.In the delegate msdn entry there is no invoke member. At least not when I look for system.action or system.func.Where can I found begininvoke documentation? what will happen if I put nothing as callback function for example? Intuitively the program simply don't call any call back function but hei, I want to makes ure of it.
View 3 RepliesInvoke Or BeginInvoke Cannot Be Called On A Control
Nov 16, 2010I have an annoying bug which is very difficult to replicate. When I start my application, from time to time, I get this error message "Invoke or BeginInvoke cannot be called on a control until the window handle has been created". This makes the user think the application is unstable... I have no idea what could cause this problem. The application uses a splash screen. It's built in Visual Basic using VS 2010 and .net framework 4.
View 1 Replies.net - Choose To Learn .NET Or C#?
Feb 22, 2011Possible Duplicate: Which language should I pick up: VB.Net or C# I'm trying to make a descision on learning VB.NET or C# as my first .NET language. I'm aware that bith languages can achieve the same things since both ultimately use the .NET framework. I'm also aware that C# has a similar syntax to both Java and C/C++, so I definitely see the benefits with this.
But how about the future of VB.NET? Will it be maintained in the years to come?I do know a bit of python, so would that make C# easier to learn?
Learn C# As Programmer?
Jan 13, 2010I am looking to switch to C#. I come from a C / C++ background but C# is a little different for me. I am switching mainly because of Silverlight and MVVM; all examples are in C#. Any information is in C# and I am confused when I read through it all.
What is a good place to start learning C# when starting with existing C / C++ knowledge?
Want To Learn How To Program
Mar 16, 2012I'm a high school teacher and I have started a course in how to program with Visual Basic. Start with the 1st entry at url...
View 3 RepliesWhat's The Best Way For A C# Developer To Learn VB?
Mar 26, 2009I'm a C# programmer who needs to pick up some VB. The syntax differences are easy enough to figure out, but there are other things I'll need more of a tutorial on. For example, VB's "strict" mode in Visual Studio is something essential to me, but something I wouldn't have learned just by comparing language syntax. Any recommendations on how to pick up VB quickly, yet thoroughly? I can't stand to work through a 1000 page book introducing VB to novices.
View 10 Replies'Invoke Or BeginInvoke Cannot Be Called' When Closing A Window
Mar 26, 2012I have a thread that loads a control from the database during a long running operation. If I close my window before that thread finishes, it throws a Invoke or BeginInvoke cannot be called on a control until the window handle has been created., when doing the Invoke.I've modified the code to look like the following:[code]However it still hits the Invoke line and throws the error. When debugging stops on the exception, IsDisposed is true, .Created is false, and .IsHandleCreated is false.how do i prevent it from running the invoke line in this situation?
View 1 RepliesC# - Abort A Thread Started With Delegate.BeginInvoke?
Feb 1, 2010Disclaimer: I know that Thread.Abort is evil. I'm using it as a last resort since some I/O functions (e.g., File.Exists when used on a non-existing network share) block for a large amout of time and do not allow you to specify a timeout.
Question: Is it possible to Abort (as in Thread.Abort) a worker thread started using Delegate.BeginInvoke or do I have to do the Thread handling myself?
Trying To Understand Control.BeginInvoke Code Over At MSDN
Jun 9, 2011I am referring to this document on MSDN. I understand what ".BeginInvoke" does, however looking at the example code on the document.[code]The delegate myDelegate (and the DelegateMethod) accepts a control and a string, but, at the .BeginInvoke, a Label control is passed and an array.[code]Shouldn't a string be passed instead of the array? Am I missing something?
View 2 RepliesUpdate Ui Content While Inside Dispatcher.beginInvoke
Apr 28, 2010i am using wpf,vb,vs2008,.net framework3.5, in my application i am trying to show one progress dialog during the calculation done in backend.so i am running progress dialog and then in a new thread i am executing the calculation operation using dispatcher.begininvoke(priority normal). in this dispatcher operation i want to update the progress dialog .if i am trying to do somethimg then that update after the completion of dispatcher operation only .i want to show the message in mean time.
View 1 RepliesUpdate Ui Content While Inside Dispatcher.beginInvoke?
Feb 26, 2010i am using wpf,vb,vs2008,.net framework3.5, in my application i am trying to show one progress dialog during the calculation done in backend.so i am running progress dialog and then in a new thread i am executing the calculation operation using dispatcher.begininvoke (priority normal). in this dispatcher operation i want to update the progress dialog .if i am trying to do somethimg then that update after the completion of dispatcher operation only .i want to show the message in mean time.
View 1 RepliesIDE :: Learn The Microsoft Reports In .net?
Apr 9, 2009I would like to learn the Microsoft reports in vb.net.Anyone can provide me the links?
View 2 RepliesLearn How To Work With Databases
Apr 1, 2011I am wanting to learn more about databases and how to code them into my VB application. I've been searching the forums and I see a lot of examples of code with OleDB.OleDBConnection, OleDBCommand and same with SQL. How did you learn how to work with databases? What resources would you recommend? Any online tutorials that you found helpful?
One of the particular issues that I am having is that I've set up a table with approximately six columns. I have this shown on the main form as a datagridview with only two of the columns shown. To edit / add a new record, I have set up a button to load a new form with the details of the datagridview showing in textboxes (for all six columns). So, if the user were to select an entry on the main form page and then click on the edit/add button it would bring up the row's information in their respected textboxes. From there the user would be able to edit and then save the changes. I'm having difficulty bringing up the form with the selected row's information.
Learn Pascal And Now Moved On To .NET?
Jan 27, 2010as part of my alevel course i had to learn Pascal and now moved on to VB.NET.in Pascal there was a data type called 'real' where a number could have floating point values) my question is this; what in VB.NET is the equivalent to the Pascal real??
View 3 RepliesVB Web Developer Wanting To Learn C#
Jul 28, 2011I've been an ASP.NET VB.NET Web Developer for the past 4 years, but its been mainly self-taught so I think theres a fair few basics I have probably not learnt along the way.I'm interested in switching to C#, and was wondering what book would be best to buy to learn this.Is Jon Skeet's 'C# in depth' book a good place to start learning, or would this be too difficult for me to start with?
View 4 RepliesWhere To Start To Learn Database
Jul 6, 2009please can anyone tell me where do i start to learn database???please help me because is a lot and confused information in google.
View 1 RepliesInvoke Or BeginInvoke Cannot Be Called On A Control Until The Window Handle Has Been Created?
Mar 5, 2009i AM TRYING TO USE A THREAD TO UPDATE SOME CONTROL during runtime using invoke and i get this message.here is my scenario:im trying to build a performance monitor tooli have a mainform that is MDI parent and i create mdi child using
[Code]...