I am new to making events and I have read up on them to further my understanding of them, and I have come across a situation that I am stuck at. Currently I have a handful of classes (lets call them a childform) that are all inherited from a class that's a form (lets call it a parentform) with an event called UpdateData(). When these forms are created they are added into a hashtable of ParentForms then added into another form. I call on these forms through a method that returns the form from the hastable. [code]....
Imports System.Threading Public Class TestClass Private myClassThread As New Thread(AddressOf StartMyClassThread)
[code]....
The result:Application runs, no errors or exceptions.Displayed is the listbox and the Start button.I press the start button and a msgbox says "Not Invoked" as expected and upon clicking OK to that msgbox "Start Button Pressed" is added to the Output listbox control.Immediately following that the msgbox pops up again and says "Not Invoked". I was expecting "Invoked" as a separate thread is trying to use the Output listbox control.Of course this results in the Output.Items.Add being attempted which results in no visible result as the thread is not allowed to directly update the UI control.
I have written a class that handles my socket information, which means i need to raise events back to my form class using a delegate. But for some reason the following does not work: -
Public Class Form1 Private WithEvents objEthernet As Ethernet Dim Eth As New Ethernet
[Code]....
Both of the Disconnected and connected events fire and are working from my socket thread but when i call "CallPassData" i get the following error "Invoke or BeginInvoke cannot be called on a control until the window handle has been created"
The problem is that, when I call the "SetStatusBarText" sub from another thread, InvokeRequired is True (as it should be), but then my threads stall on the Me.Invoke statement - pausing execution shows them all just sitting there, not actually invoking anything.
anyone know how to invoke the KeyPress event ? This code shows what I would like to do, but it simply calls the eventhandler and does not insert the text into the text box, so is not what I want/need.
I would like to know how can I invoke a event on a control? By e.g. I have an user control (myUC) that I drag on a panel (myPanel). When the user MouseClick s myUC and drag it I would like to send the MouseClick Event
I want to invoke a method on a class that i have a reference to. The method that I want to call has a custom attributes. Currently I can find this attributes and call the property of my class Attribute.
is there a way to invoke that method ?
PS/ The project is written in vbnet, but I think the solution is the same in c#.
I actually know how to do this but this one is a little tricky because I don't see an "Id" for the button, all I am noticing are classes. The button originally says "3D", then when you click on it it says "2D", if you click on it again it says "3D", and so on...here is a snapshot of the html code behind the button
HTML <td id="dir3d"> <a href="javascript:void(0)" class="kd-button mini p3d" jsaction="click:dir3d.play"> <span class="dir3d-text">
I am making use of a serial port in a class. I am raising an event from that class to my form calling the class. Event contains data received... I wish to simply populate a textbox from the raised event.Now I am not specifically creating a seperate thread, but I get the normal crossthreading error when trying to update my textbox on the UI, so my assumption is that the serial port and its internal methods probably creates its own threads...Regardless, I am a bit confused as to how to properly implement an invoke, from my main form, pointing to the thread in the instantiated class...
Dim WithEvents tmpRS232 As New clsRS232 Private Sub but_txt_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles but_txt.Click tmpRS232.Set_com_port("COM8", 38400)
It was pretty simple in VB6 to invoke the 'click' event of a command button (i.e.; btnNext_Click). I am having difficulty trying to do the same think in VS2008.
I am getting errors at line btnNext_Click(): Error1Argument not specified for parameter 'e' of 'Private Sub btnNext_Click(sender As Object, e As System.EventArgs)'.
Error2Argument not specified for parameter 'sender' of 'Private Sub btnNext_Click(sender As Object, e As System.EventArgs)'.
I've have a editable pdf with button fields in it. I'm processing this editable pdf in my vb.net application using iTextsharp. I want to know, how to programmatically invoke the button field inside the pdf. Though, I'm using iTextSharp dll, i could not find any helpful resource to invoke and handle the button events. Please guide me how to invoke the button events of pdf, programmatically using vb.net.
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)
I have a filesystewatcher object. On it`s event it runs a procedure which fills a treeview with a data. I had problems with treeview methods, but when I run them using invoke method everything is ok. But I still have one problem. When I load the form for the first time, everything works fine. But, when I then close the form (me.dispose, me.close), and load it once again, when Filesystemwathcer start the procedure i have an exception "invoke or begininvoke cannot be called on a control until the window handle has been created" trying to run a treeview.invoke method?
I have a class that is stored after serialization and compression.Is there any event built in the class that is fired automatically when a class is deserialized and ready to be used??
We have a UI with a progressbar. I know how to invoke, safely, the control from which it was not created from a thread. there are threads being processed in a threadpool, all of which calls an "agent" (which is a notifier to raise an event back to the UI to then increase the progressbar). an "agent" is set as a property in a State object, which is then passed into a method which will be executed on the ThreadPool. so, I invoke on the UI the method to update the progressbar, but the bar does not seem to update at all (screen frozen) and it takes a very very long time for it to execute. without threading, no problem.
I have a "partial" class in VB.NET. Half of it is auto generated by a code generation tool. That half implements INotifyPropertyChanged, so any properties in that part of the partial class raise the PropertyChanged event.In my "custom" part of the class, I declare another property that depends on one of the properties in the auto-generated side. Therefore, when that auto-generated property changes, I also want to raise a PropertyChanged event on my custom property that depends on it.
If I go into the generated part of the class and raise the event there, that will get overwritten if I ever re-generate that part, so I don't want to do that. I would rather add an event handler in my side of the partial class that checks if the generated property changed, and if so, raise another event for my custom property.
[Code]...
I'm assuming it's because normally you'd use the WithEvents keyword to tell the compiler that you're subscribing to events from that object. I don't have a clue how to do this inside of the class that's actually raising the event, or if that's even possible.
I'm writing a Windows Forms application in VB.Net 2008, .NET Framework 3.5, and I am trying to handle an event created by a class that get's instantiated several times throughout the program. The thing is the events gets fired in the Functions class, but nothing's happening in the main class.I tried to change the called class by instantiating it in the beginning of the main class, by using 'WithEvents testEvent as MTO_Tool.Functions = New Functions' but that also didn't work.
Code:
' The main class: Public Class MainScreen WithEvents testEvent As MTO_tool.Functions Private Sub test() Handles testEvent.SaveChanges
I have 2 classes one main class called Mygrid and another class inside it called TLBoxEditingControl which inherits a textbox into grid cell.Also I have added one Listbox called LstBox to the usercontrol MyGrid.
1) Initially its visible is false. How can i make visible true in TLBoxEditingControl class.
2) I have an Event called MyList() in Main Class, how can I raise this event in TLBoxEditingControl class.
Here is the code i use, This is not working please expalin
Public Class MyGrid Inherits DataGridView Public Event MyList()
[code]....
I have added this control to a form and added this code
Private Sub MyGrid1_MyList() Handles MyGrid1.MyList MsgBox("ggg") End Sub
In .NET I have a class called Caption. I have another class called Gauge. Within the Gauge class I have a property defined as a Caption.I am trying to figure out how to do thefollowing:When a certain property is changed in my Caption class how do I get it to execute a subroutine in the Gauge class? I am thinking I have to declare an event and AddHandlers to fire it off, but I can't think of how to accomplish this.
Can i add an event to a Public NotInheritable Class?, in particular i would need to have an event that would listen to property change.System.Web.ClientServices.ConnectivityStatus has a property IsOffline, i would need to know when this property has changed?
Basically, I have a custom child form class which has events that will be passed to the parent. In the custom child form, I have a declaration of a "MustInherit" class that inherits the DevExpress User Control Class.
The reason for this, is I have many user controls that derive from this base class, and the child form can have an instance of any one of these controls, and doesnt care which. The only requirement is that the child form can handle the same events from each type of control the same way.
Some watered down code snippets(still pretty long unfortunately): '''Inherited Class Public Class ChildControlInheritedClass
I haven't quote grasped this whole "class" concept yet, but I'm working on it. When following the instructions below, the "test" portion of this code: "test.variable". It has an underlined error that says that "test" is not declared. If I remove the "test" word then the ".variable" shows not declared. I'm using Visual Studios 8 if that makes any difference. I have a pre-existing variable in a project that I would like to monitor for changes.
Re: Detect variable change. Make your variable a class with an event. Make your class: VB.NET Syntax (Toggle Plain Text) Public Class myVar Private mValue As Integer Public Event VariableChanged(ByVal mvalue As Integer) [Code] .....
I have a form that contains a DataTable variable (dt) that has a RowChanged event assigned to it. I use a UserControl (DataGridViewFilterAndSorter) to get a subset DataTable from dt. I need dtSubset to have the same event as dt. How can I do this?
In other words, I need to pass the dt event to the DataGridViewFilterAndSorter class and store that event as a class level variable. How can I do this?
Public Class frmCalculatedResults Private dfs As DataGridViewFilterAndSorter Private WithEvents dt As DataTable
I have a Windows Service project designed to monitor an email account and make entries into a SQL Server database when certain emails arrive. This is a rewrite of a similar winforms program that works just fine, except that it requires that the computer be logged into an account and the program started manually, which I can avoid by using it as a service.In the service I maintain a list of logged messages - basically just a string and a timestamp indicating that something has happened. (That list is shared out over a WCF service but I think that's immaterial, at least at the moment.) In my custom class I declare a public event, and elsewhere I raise that event. For some reason, though, the RaiseEvent isn't being run in the service. For example:
[code]...
The problem in this case is that _pc_HandleEvent isn't ever being called. If I duplicate this setup in a regular winform program, everything works like it should. What am I doing wrong? How do I get a service to handle events raised from other classes?
