I have a couple of threads running. One is a trigger which picks up a system event, the other processes stuff. When the trigger picks up the event I want it to notify the processor thread to do stuff. The threads are both started within the same class and can access the thread-object of the other thread. How do I set up the function call though?
View 10 Replieswhen I try to perform a cross thread call to fill a text box with messages with the following code I have no problems:
Delegate Sub SetTextCallback(ByVal [text] As String)
Public Sub SetStatusBox(ByVal [text] As String)
If Me.statusBox.InvokeRequired Then
[code]....
However, I am having problems when I use the following code to do a cross thread call to close a form. The form just hangs there.
Public Delegate Sub setFormClosing(ByVal ctrl As Control)
Private Sub closeForm(ByVal ctrl As Control)
If Me.InvokeRequired Then
[code]....
I created a STRING SEARCH function in C/C++ - and I'm trying to use it in a multi-threaded situation in VB. I started this problem in a thread in the C/C++ section of the forum - here [URL] my last post shows me getting this error trying to call the function. Ran the code - got to that point - and in the immediate window I did
[Code]...
My understanding is that thread.join will suspend the execution of code on the calling thread until the spawned thread finishes or is aborted...
With that in mind, I tried this:
For i = 1 to 50
threads = New Thread(AddressOf test)
threads.IsBackground = True
threads.SetApartmentState(ApartmentState.STA)
[CODE]...
However, the rest of the code runs when the loop finishes, not waiting for all the spawned threads to finish. Since the rest of the code needs the threads to finish (otherwise the rest will error).
I am trying to call a method that started on a background thread on the UI thread calling BeginInvoke and passing in a delegate as follows:
Dispatcher.BeginInvoke(Function() UpdateApplicationDataUI())
to call this method:
Private Sub UpdateApplicationDataUI()
...
End Sub
However, I get an error in the call to BeginInvoke (the UpdateApplicationDataUI portion of the delegate is stating "Expression does not produce a value").
Me.Dispatcher.BeginInvoke(Function() New Action(AddressOf UpdateApplicationDataUI))
I have am using a Twitter streaming class library, and would like to update a listbox when a new tweet is posted. I have it all set up to the point where a message box will show when a tweet comes in, but when I try to insert this tweet into a listbox I get this error: The calling thread cannot access this object because a different thread owns it. I don't know what I need to do in order to insert this tweet.
View 4 RepliesMy routine to check for updates is run as a separate process. Exiting the application is required to update, so a dialog asks the user, when an update is found, if they want to exit now. f they do, the code (from the update thread) calls Application.Exit().However, if the FormClosed event of any form that needs to be closed needs to access its controls, an invalid cross-thread operation is detected (which sounds pretty logical).
View 1 RepliesI'm currently working with a client's VB.Net code, which was developed for them by a small development shop a few years ago and which they purchased and have been maintaining and uprgrading since. This client's primary developer is out on indefinite (likely permanent) medical leave and I'm now filling in until they bring in a full timer (as I'm a contractor here). My current task is to add some functionality to a the VB.Net code they purchased. I'm finding practices and techniques in the code that absolutely baffle me and can't make the code do what I want. I'm starting to wonder if it's me and was hoping to get some thoughts on the code I've encountered.
For example: Setting a variable to accept the result of a function by calling the function with many parameters, clearing the parameters in the function, setting them to some value, calling another function with those new values, then never using the values returned by the functions. I'll add a code snippet in the first comment since this is already getting long.
A non-UI thread in my prog needs to obtain data from a UI listview control. To prevent cross-thread errors I use the following, but it freezes the prog (probably because the "Else" part is never called).What am I doing wrong?
[Code]...
I have a function where I am performing a lot number of database operations inside a Sub. The operation when called directly like:ExecProcess()
takes about 11 seconds to run.However, if I create a Delegate, and call the sub using BeginInvoke(), the very same process takes over 40 seconds to execute.Here's the threaded code:
Protected del As ProcessDelegate
Protected Delegate Sub ProcessDelegate()
del = New ProcessDelegate(AddressOf SELocal.ExecJob)
Dim cb As New AsyncCallback(AddressOf Me.ExecJobComplete)
del.BeginInvoke(cb, del)
Anyone know what may cause a function to take longer inside a new thread, rather than calling directly?
I am having a problem with the BackOrdered Function of my program. I can`t get it to say anything but 0 when I run the program. Another problem I am having is the input box pops up like 6 times and it`s only suppose to once. [Code]
View 9 RepliesSo 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.
I cannot grasp this issue. In the below code. I am trying to start a separate thread to display a progress bar while a function is executed in the main thread. The function can take a while, and during that time the program appears to just lock up. So, the progress bar does not really need to show the progress it just needs to cycle till the main thread function is done executing so that people know that the program is still running.
[Code]...
A thread listens for incoming information from a server will add the received string to a custom control (containing a textbox and a listbox, I've called it console). This requires an invoke so I used the following
Dim InvWriteCons As Console = Gary.ChatCons
Dim INvWriteText As String = "DEFAULT"
Public Sub InvWrite(ByVal cons As Console, ByVal message As String)
[code].....
I have used the PInvoke Signature Toolkit to create VB.NET function definitions for three fairly simple C functions contained in an external DLL. The problem is that two of the parameters are structures so pointers need to be sent and one structure (fileview) is undefined.
OpenFileView(filename, &fileview_ptr)
ReadFileInfo(fileview_ptr, &fileinfo_ptr)
The structure of fileinfo is defined so I can create a structure definition in VB.NET and create an IntPtr to that structure with Marshall.AllocHGlobal. And then I can use Marshall.StructureToPtr to copy the data and do the inverse when the data is returned.
[Code]...
I'm having some problems calling a C function from a DLL. The function is returning -101 which translates as a "bad parameter". The values I am passing have been returned from another, successful function call, so my current assumption is that I've built the structure incorrectly.The function definition is:
int sm_switch_channel_input(struct sm_switch_channel_parms *switchp)
Parameters
*switchp (a structure of the following type):
typedef struct sm_switch_channel_parms {
[code].....
in a DLL that takes a pointer to a structure as a parameter.The C and VB code is as follows.Am I passing the structure in calling the DLL correctly? I am asking because the API call returns a valid error code indicating error opening the com port specified. I tried all valid ports (com1 on a Vista 32 machine with a USB-Serial device and com1 defined in device mgr, com1 and com2 on a desktop with winxp and 2 real serial ports).I dont have the code for the DLL and cannot debug into the DLL code.
C code
typedef struct _SETUPPR {
CHAR Port[5];
[code].....
I'm sure this is a pretty simple question but I can't seem to find the answer on Google. Say I've got a function that does some stuff and returns a string. I can assign its return value to a variable:
Dim result As String = MyFunction()
But sometimes I want to perform the actions within the function but I don't care about the return value. I know I can simply call the function from code.
Sub Main()
' Code
MyFunction()
' More Code
End Sub
This works and does exactly what I need it to. My question is - are there any issues or pitfalls in doing this? Particularly I want to make sure I'm not introducing any performance or memory leak issues.
The function is something like this: "function recieveFindPlayerResponse(displayString)"Now, how can I call it. I was trying this:Call AxShockwaveFlash1.CallFunction("_root.recieveFindPlayerResponse(displayString)")And before I had this, I had a Call function which defines displayString. (Works, as I've tested it before, and no error is given to this.)Now, how can I call a function like the above?
And example of what the code looks like from ******* swf decompiler is:
function recieveFindPlayerResponse(displayString)
{
[code].....
in VVB.net I have a string that contains the name of a function, say dim funcstr as string = "MyFunc1". How do I call the function or sub whose name is contained in the string funcstr (in this case, MyFunc1)?
View 9 Repliesgoing to need to call unction within a FoxPro program. I believe within my VB program I will need to create a service which will need to cal
View 7 RepliesI have an aspx page populated with data from an access database using this code:
<asp:datalist id="bookData" runat="server" RepeatDirection="Horizontal" RepeatColumns="3">
<ItemTemplate>
[Code]....
I would like each entry of data to have a button associated with it that could call a server function to submit data to a database. I currently have the button implemented, but no idea how to go about calling a function that would be able to detect what button was clicked.
i have this question i was trying to find a way to call a javascript function from asp controllers and i did here is the code :
<script type="text/javascript">
function hello() {
alert("hello world")
[Code]....
and i want to call it from a javascript function so it will be like controller----call---> javascript ---call--->code behind
I've designed a Windows Service in Visual Basic 2005 that needs to call some functions from a DLL written in Delphi 5. If I try to add this DLL as a reference, I get this error:
"A reference to 'C:ProjectsServiceProMDPUpdateServiceMessageStubApplicationSPHost.dll' could not be added. Please make sure that the file is accessible, and that it is a valid assembly or COM component."
I assume that it is just not possible to add this DLL as a reference to my VB2005 project, since the DLL was written in an old version of Delphi, correct? This isn't a big deal, as I can just use the DllImport function from System.Runtime.InteropServices, but if it is possible, adding it as a reference would be preferred.
My other question is, how would you be able to call a function from the DLL using DllImport, if the function you are trying to call takes a Delphi record data type as a parameter (if this is possible)? If possible, would I need to pass each field in the record separately or would I be able to define a structure in my VB app that mirrors the record definition in the Delphi DLL and pass that? Or, would it be best if I just created another function in the Delphi DLL that took various string/integer/boolean/etc. parameters that I could call from VB that would then call the original function in Delphi? I tried searching the internet for this specific question, but I couldn't find anything that looked useful.
[Code]...
I have an XML file with a list of tasks to be executed. One of the elements of the XML file is funcName (function name), which is the name of a function to be executed in my Visual Basic.NET application (v4).I can retrieve the string name of the function, but how do I go about running it? I have two Class files, GUI and DISP.[code]
View 2 RepliesIs it advisable to call a function from another form?Does it have any side effects on the system while running, like more process will consume?I have a function that will set the background in a form, it will make the image stretch, backcolor transparent and will set the picture. If I will use that function in other 15 FORMS I can minimize my code.
View 9 RepliesI have an 100 aspx files with one module file for code. All these aspx files have the same backend function, so i created on public module for all these files to access. These files are in the same folder. But for some reason the aspx files cannot access the function from that module.
mod1.vb Code (.vb file)
Public Module Allinone
Sub Allinone_Load(ByRef Page As Web.UI.Page)
[Code]....
I am at a roadblock of why the aspx files wont read this module? Also all these files are in the same directory
Question: I want to call a generic function, defined as:
Public Shared Function DeserializeFromXML(Of T)(Optional ByRef strFileNameAndPath As String = Nothing) As T
Now when I call it, I wanted to do it with any of the variants below:
Dim x As New XMLserialization.cConfiguration
x = XMLserialization.XMLserializeLDAPconfig.DeserializeFromXML(Of x)()
x = XMLserialization.XMLserializeLDAPconfig.DeserializeFromXML(GetType(x))()
x = XMLserialization.XMLserializeLDAPconfig.DeserializeFromXML(Of GetType(x))()
But it doesn't work.I find it very annoying and unreadable having to type
x = XMLserialization.XMLserializeLDAPconfig.DeserializeFromXML(Of XMLserialization.cConfiguration)()
Is there a way to call a generic function by getting the type from the instance ?
wondering if there was anyway I could call a function of an external program. Ie.My App:Call Reset()External App:Reset()My.Settings.Rese
View 4 RepliesIs it possible to call a function within an asp.net web application from outside that application e.g. with VB.net? If so it would be great to see a hello world type example.
For arguments sake lets say I have my function "helloworld" in a class file within web application: [URL]
My ultimate goal is to enable some reliable / robust scheduling of functions within asp.net. I have read multiple examples about using web services / custom services running on the server etc but I don't really get the implementation.