Catching Raised Events?
Apr 5, 2011I have read the documentation on RaiseEvent and Even but still confused. I am using a class that i call that performs a task on a thread.
vb
Public Property MyVar As String
Public Sub MuSub()
[code]....
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.net - Record And Replay Raised Events?
Mar 13, 2012I implemented the communication between two classes by using events in VB.Net.Now I want to store (record) all events that occure and to re-raise (replay) them again later.
Here is what I have already:
Class1:
Public Event Button1Pressed(ByVal sender As Object)
Private Sub btnButton_Click(ByVal sender As Object, ByVal e As EventArgs) Handles btnButton.Click
RaiseEvent Button1Pressed(Me)
End Sub
[Code]...
I could add another handler to the event I want to record, but then in the handler I only get the parameters that are passed to the event and not the event itself.Another thing I don't know how to solve is, that I can't raise an event from an extern class.
Event Handler Does Not Catch Raised Events?
May 12, 2011I have a test class with an implementation similar to this:
public class MyObject Public Event testEvent(ByVal duh As Boolean)
Public Sub New()
'some code here
End Sub
[Code]...
.net - Events Raised By BackgroundWorker Not Executed On Expected Thread
Mar 22, 2010A 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.
.net - Should Events Be Raised In New Threads To Not Block Current Work?
Dec 15, 2009I'm currently designing an assembly that will be used by third parties. One of the classes has a long process of TCP connections and it informs about its process using events. For example
''# Do stuff that takes some time
RaiseEvent CompletedFirstPartEvent()
''# Do stuff that takes some time
[Code].....
What I've seen if that if the handler of one of those events takes too long (or even worse, it blocks) I can have timeouts and it's hard for the developer to see that one class is not working fine because his handler is taking too long.
I was going to fire the events in a new Thread to avoid this issue but this looks strange to me because I've never seen something like that, what I've seen until now is the developer spawning a new Thread if his handler was going to be timeconsuming. So the question is:
What would you do? Create a new thread or force the user to create his own thread? (Or is -there a better approach that I don't know?)
Catching Application Crash Events
May 9, 2012I made a application in VB.Net. But some users face crash upon startup. That is "A problem caused this program from working correctly" with just one button "Close the program". Since there are lot of things happening when the app loads
View 1 RepliesCatching Events In ArrayList Of Objects
Jul 22, 2009I have an ArrayList that is populated with Objects. These Objects raise events at certain times. How can I capture these events from the ArrayList? i.e.
I want something like this:
Public Sub MyRaisedEvent(ByVal obj as MyObject) Handles MyArrayList.MyEvent
End Sub
Catching Exceptions Thrown By Controls Events?
Jan 5, 2011I've a control that throws an exception in one of its events and I need to catch this exception. How can I do this?
Example:
Private Sub AxNtlxImage_Reason(ByVal sender As Object, ByVal e As AxNTLXIMAGELib._DNtlxImageEvents_ReasonEvent) Handles AxNtlxImage.Reason
' TODO: Deal with this reason message
Throw New ArgumentException(e.sText)
End Sub
I want to catch this exception from another procedure when it happens.
Catching Mouse Events For A Custom SplitContainerDesigner
Jul 16, 2010I'm trying to create a user control that will provide a draggable splitter between two panels — exactly like SplitContainer — in a custom IDesignerHost implementation. SplitContainer itself, as far as I can tell, is not an option; it will raise an exception unless used in Visual Studio's Designer.
My implementation would look roughly like this, except that I'm not receiving the necessary mouse events. I've tried event handlers, On* overrides and overriding WndProc in the user control itself, the host control, and the parent form, but I don't appear to receive WM_MOUSEMOVE, WM_LBUTTONDOWN or WM_LBUTTONUP events anywhere. Per this bug report, I should be receiving WM_MOUSEMOVE in "the control designer"; I'm not sure what that refers to in this case.
how I can implement a draggable splitter?
Catching Mouse Events For A Custom SplitContainerDesigner?
Jul 22, 2009I'm trying to create a user control that will provide a draggable splitter between two panels — exactly like SplitContainer — in a custom IDesignerHost implementation. SplitContainer itself, as far as I can tell, is not an option; it will raise an exception unless used in Visual Studio's Designer. My implementation would look roughly like this, except that I'm not receiving the necessary mouse events. I've tried event handlers, On* overrides and overriding WndProc in the user control itself, the host control, and the parent form, but I don't appear to receive WM_MOUSEMOVE, WM_LBUTTONDOWN or WM_LBUTTONUP events anywhere. Per this bug report, I should be receiving WM_MOUSEMOVE in "the control designer";
View 4 RepliesWhy Is Event Being Raised Twice
Sep 7, 2010This is the abstracted code for simplicity.
Public Class Form1
Dim WithEvents bt As New Button
Private Sub Bt_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles bt.Click
MsgBox("Click")
[code]...
ASP.Net Event Only Being Raised Every Other Time?
Mar 9, 2010I have an ASP.Net web user control which represents a single entry in a list. To allow users to reorder the items, each item has buttons to move the item up or down the list. Clicking on one of these raises an event to the parent page, which then shuffles the items in the placeholder control.Code fragments from the list entry:
Public Event UpClicked As System.EventHandler
Protected Sub btnUp_Click(ByVal sender As Object, ByVal e As System.EventArgs)
Handles btnUp.Click
[code]....
It originally looked in testing like every other time the value for sender (verified by its properties) that reaches UpClicked is of an adjacent ListItem, not the one I've just clicked on - the first click is always wrong, then the second for the correct control.At present,testing appears to show that the button's click event is just being ignored every other time through.Breakpoints on the click events within the control simply aren't being hit, though the events are definitely being established.
Handle An Event That's Raised In New?
Aug 23, 2011[code]But even here it seems the handler isn't registered until after New has completed.However, in real life the event is raised within code that's semantically part of the object initialisation, and I'd really rather not have to create some Initialize function.
View 2 Replies.net - FileSystemWatcher Changed Event Not Being Raised?
Apr 29, 2009I'm working on a Windows Service that watches a few folders for changes, creations, and deletions. It all works well with the exception of one watcher that watches a single file (XML File with Configuration Settings) for minor changes.
I tried taking the Windows Service code and putting it into a simple windows application with start/stop buttons for the filesystem watchers and stepped through it. It never detects the file change of the XML config file. The changes are indeed occurring and the "Date Modified" of the file is updating.
XmlEventReferences = New System.IO.FileSystemWatcher()
XmlEventReferences.Path = "C:XmlReferences"
XmlEventReferences.Filter = "*.xml"
[Code].....
AccessViolation Exception Raised While Calling A VC++ Dll?
Jul 15, 2011We are trying to call a VC++ unmanaged Dll from VB.net 4.0 application. During execution the application breaks and gives AccessViolationException(Unable to read or write protected memory). When we press F8, F10 or F5 it continues execution and give us correct results. And it is anonymous i.e. sometimes it works cleanly sometime it breaks. We tried everything ( debugging the Unmanged code, different ways to create unmanaged dll etc..).
Vc++ method signature: unsigned long LZCompressBuffer(unsigned char *SrcString, unsigned long SrcLen, unsigned char *DestString, unsigned long DestLen)
VB.net calling: Public Declare Function LZCompressBuffer Lib "CompExpand.dll" (ByVal buf() As Byte, ByVal slen As UInteger, ByVal dstr() As Byte, ByVal dlen As UInteger) As UInteger Mostly it generates error in memcpy() (String.h) method
Display Something When Basic Event Is Raised
Jul 27, 2010I want to write an event that will simply display something when it is raised. I have never really worked with event driven programming before and am just trying to get a simple example working. It is not yielding any errors, but when I switch to debug mode I can see that the event it not raising correctly.
[Code]...
Dropdown In UserControl - Event Is Not Raised
Jan 11, 2012I have a user control named "LettersDropControl". It has a dropdown list. I am using this control in a aspx page. When I change the selected item it is not calling the ddlLetters_SelectedIndexChanged event handler? What change I need to make in order to execute the code in ddlLetters_SelectedIndexChanged event handler?
<%@ Control Language="C#" AutoEventWireup="true" CodeBehind="LettersDropControl.ascx.cs" Inherits="MSAJAX1.LettersDropControl" %>
public partial class LettersDropControl : System.Web.UI.UserControl {
private string selectedLetter;
public string SelectedLetter {
[Code] .....
Handle An Event Raised From A MODULE?
Mar 2, 2011I must be missing something really basic, but I just can't figure this out. I have a module (declared as a Module, i.e. a VB "static class") and I have an event declared in it, and places to raise the event. But I can't figure out how to handle the event.
Let's call the module MyModule with an even MyEvent. Like so:
Module MyModule
Public Event CallHelp()
Sub ExamineStuff( ByVal input As String)
[code]....
Determine Whether A Form Has Raised Its Shown Event?
Aug 5, 2011I have an MDI application that can either run in TABBED or WINDOWED mode. When a user selects something from the menu a form is shown. All menuItem clicks pretty much look the same:
Dim frm As New <SomeForm>
frm.MdiParent = MDIParentForm
frm.Show()
[code].....
Event Raised In Constructor Cannot Be Handled Outside Very Class
Oct 26, 2009I discovered that an event raised (directly on indirectly) in the constructor cannot be handled outside the very class. To prove if that was the actual problem, I wrote a simple exemplary app.
Class with the event:
Namespace Utils
Public Class A
Public Event Test()
Public Sub New()
CallTest()
[Code] .....
The reason of such behavior became quite obvious after writing those pieces, but maybe there is a way to omit it?
Get Index Of Item In Collection That Raised Event?
Jun 30, 2010In a list of timers, how do I determine the index of the item that elapsed without having to iterate the collection as shown below (e.g. can I pass a paramater to OnTimedEvent, or can the collection raise an event to say which item fired???). It's the individual timer index that I need as I'm using it to refer to something else.
(I wont know how many items I'll have in the list in advance so I can't create an individual event handler for each timer - I don't think I should even if I did).
Public Class Form1
Private _timers As New List(Of System.Timers.Timer)
Private Sub Form3_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
[code]....
VS 2005 Stopping Event Raised With Timer?
May 2, 2009I'm new to VB and relatively fresh in programming in general. I'm trying to write code to make a label flash red. The method involves using a timer. Problem is, it flashes, but I can't figure out how to make it stop. xD Here's my
Private Sub SeleneExplainsToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles SeleneExplainsToolStripMenuItem.Click
lblNumbers.ForeColor = Color.Red
Timer1.Enabled = True
AddHandler Timer1.Tick, AddressOf OnTimerEvent
End Sub
[Code]...
VS 2005 Update UI In Event Raised From Thread?
Jul 3, 2011I want to raise an event from a non-UI thread where the event will be handled by the UI. Currently, I have to use .Invoke in my methods (which updates UI) called from the event.
How can I raise the event, similar to Background Worker's progress update event, where I don't have to specifically do an .Invoke for UI updates?
Do I wrap the event with a delegate or something? Sample code will be fine though, if the explanation was tedious.
VS 2010 SelectedIndexChanged Raised On Each Mouse Click?
Nov 22, 2011If you set a listbox selectedindex in code the SelectedIndexChanged event is only raised if the item isn't already selected, So why is the event rasied when you click a selected item with the mouse?
Here's what I came up with to get around the problem (which seems unnecessary and silly), So if there is a built-in or better way I'd sure like to know.
[Code]...
Button Click Event Is Raised Twice In Silverlight Project?
Feb 28, 2010I have a central page loading child controls into a container in a Silverlight Project.Problem is events like button click events are fired twice after processing the child forms.Suspect it might have something to do with a double initializecomponent??
Private Sub btVolgende_Click(ByVal sender As Object, ByVal e As System.Windows.RoutedEventArgs) Handles btVolgende.Click
Select Case Stadium
[code].....
Make Customized Borderstyles, Create 'raised Area' Looks?
Jul 12, 2010I've been working with System.Drawing for awhile and like to think I have a good handle on it; I've created classes that draw grids, write text in gridboxes and rectangles, convert rectangles to circles, fill areas with color, etc. What I don't have is any sense of artistry at all, and I don't have the slightest clue how one would use System.Drawing to draw a rectangle and then color/slope the edges so that it looks like a System.Windows.Forms.Button would, or how to make it look like it's inset deeper than the surrounding Form, like setting a Panel's BorderStyle to Fixed3D.
View 3 RepliesUser Control Button Click Event Not Raised
Nov 4, 2010I have a User Control that has been added to the page dynamically. When I click a button on that user control[cod]e...
View 2 RepliesVS 2005 Test What Event Has Raised In A Multi Handler
Jun 2, 2010I want to know what the Event has raised in a multi handler.
[Code]...
Winform Event Raised In Subclass Won't Sink In Form
Aug 2, 2011I'm trying to capture the initial value of a listbox immediately after it's clicked on, and before the SelectedIndex is changed. The following was taken from: MouseDown in WinForm ListBox Kills SelectedIndexChanged, converted to VB. The ListBoxComponent Class is in a Component that shows at the top of the Toolbox.
Public Class ListBoxComponent
Inherits ListBox
Public Const WM_LBUTTONDOWN As Integer = &H201
Public Event PreSelect As EventHandler
[code]....
Asp.net - Catching An Inner Exception - But Only If There Is One
Mar 14, 2011I am trying to catch an exception but occasionally get an inner exception. I want to output both into a label. I often get Object reference not set to instance of an object if there is no inner exception.
Catch ex As Exception
exError = ex.Message.ToString
If Not ex.InnerException.Message Is Nothing Then
[Code]....