I have a Timers.Timer called COMTimeout, to which I add an event handler using:
AddHandler COMTimeout.Elapsed, AddressOf TimeoutEvent
however, the handler may also be:
AddHandler COMTimeout.Elapsed, AddressOf SecondTimeoutEvent
I now need to remove the handler, is there a way to do it without knowing the name or do I need to keep track of which handler as been assigned?
remove an event handler from within the event handler?
I have a class that gets data from a hand scanner. When the scan is complete and the data is validated, the class fires a custom "ScanComplete" event and returns the data in a custom EventArgs.
In the calling program, I'm creating an instance of the scanning class and adding a handler for the "ScanComplete" event. In the event handler I get the data that was scanned and then remove the handler.
It seems to be working but it feels wrong to remove the handler while I'm running inside the handler. Will this cause a problem?
Some controls are dynamically created within a panel. Their event handlers are attached
Dim btn as new system.windows.forms.button
with btn
'set properties
[Code]....
I have a TableGridLayout (6 x 6) which host 36 buttons created at design time.From the 36 buttons, only a handfull maybe needed at anyone time depending on data retrieved from an SQL database.Everytime I need to 'clear' the grid to populate with new items, I clear the text of each button, make it visable if required and then upadate with the new text.On every pass if a button becomes active, I add an event handler to the button like this.[code]...
View 4 RepliesI'm writing a small 2D engine that uses Lua to control it. I've been setting events up in between the Lua and the VB.net for the past little while here. The problem, I've realized, is that is that I can't seem to remove the events which is screwing up quite a few things (because they are being called when they should be done with). To fix this, I wanted to add some kind of way to remove the specific event handler.
I know how to add an event handler:AddHandler Button1.Click, AddressOf Button1Clicked
But with this in mind, is their a way to remove a specific event handler in the VB.net? I didn't explain this very well: If I have this:
[Code]...
VB.NET RemoveHandler & Anonymous Methods
If I add an event handler like this:
AddHandler s.Click, AddressOf Panel1_Click
How can I can then remove the event handler?
Private Sub Panel1_click(ByVal sender As Object, ByVal e As System.EventArgs)
' Remove code
End Sub
I am having a problem with the cellvalidating event constantly firing when the datagrid is refreshed (since the trigger that fires the event is the originally selected cell losing focus).I would like to remove the event handler for this at certain points of my code so that it does not fire but the examples I have come across on MSDN don't appear to do anything, so I guess I must be doing something wrong.[code]
View 1 RepliesThe event handlers in my parent class are never called though the events are raised in the child class.
The Code:
Public Class childForm
Public Event checkboxchangedEvent(ByVal checkbox1 As Boolean, ByVal checkbox2 As Boolean)
Private Sub checkboxchanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles CheckBox1.CheckedChanged, CheckBox2.CheckedChanged
[code]....
I've been fiddling with this for ages and can't get it right. If you have this in C#:
videoSource1.NewFrame +=new NewFrameEventHandler(videoSource1_NewFrame);
void videoSource1_NewFrame(object sender, NewFrameEventArgs eventArgs)
{
// stuff to do in here
}
How would write it in VB? My head is spinning with AddHandler and AddressOf and I can't seem to get it right.
How do I get a Event Handler to fire from within a nother Event Handler?
View 6 RepliesI have to create controls for inputting info to create people objects in the program, because I don't know how many people they are going to input, I have a button that they can press to add more fields.
I need to add a doubleclick event for these dynamic controls (text boxes), how can I create an event for them if they haven't been created yet. Also, as far as I know you cant make a variable part of an object name while declaring it. I need to do something like
Dim dynamicText & (Append variable counter each time a box is made)As New TextBox
dynamicText &variable counter. Name = "TimeTextBox"
dynamicText.Text = "SdgsdG"
dynamicText.Location = New System.Drawing.Point(100, 100)
[code].....
Also is there a way to like copy and paste a group of controls via code instead of having to code each individual one like if I had to do a text box along with a combo box and a lable all at once, can I throw it into something so I only have to recreate the container?
I am playing around with Drag and Drop, and I am having an issue with AddHandler. I am creating labels and displaying them on a form. Before I add each label to the form, I add 2 event handlers (DragEnter and DragLeave). When I run the code, it hits the first event handler (DragEnter), but doesn't hit the second event handler (DragLeave). Either I have coded something wrong, or the second handler is not being added.
Here is my code (note this is just something Im playing around with for learning):
Public Class Form1
Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
[Code]....
I'm new to VB and trying to add a Key(Down? Press?) Handler to a dynamicly created textbox. The error I get is "'KeyDown' is not an event of 'Object'". How do I fix this?Here are the relevant parts of my
Public Class main
Structure square
Dim box As TextBox
Dim guessedVal As Integer
Dim correctVal As Integer
[Code]...
I'm using FileSystemWatcher in an application.it monitors the files in a folder, then do some processing. I monitor FileCreate, Change, Rename, Delete event.the problem is: when I copy some images to that folder, it fired the create event, but the file is not actually ready, so, when I load the file in the event handler, it failed.how can deal with this correctly?
View 2 RepliesI have many textbox controls and they are named as txt1.text, txt2.text, txt4.txt etc.I want to raise the event "Leave" when txt1.text leaves or txt2.text leaves.but with a single handler.
View 2 RepliesI'm working on a program with a fairly complex graphical interface. Due to the volume of information possible in the interface, the tooltip, or something like it, seems likely to be a fairly critical means of obtaining feedback. However, after a bit of testing, there are a few features that I am not really enamored with. First, I am changing the tooltip text dynamically based on the portion of a control that the mouse hovers over. This is done in the Hover event handler. What I am seeing is that once the hover event is raised once for a control, it appears not to be raised for that control again unless the mouse leaves the control and re-enters. Therefore, the tooltip is set based on where the mouse hovers the first time it hovers on the control, then doesn't change until the mouse has left the control.
More disturbingly, the tooltip sometimes doesn't show up at all. It appears that if I am quick enough about moving the mouse over the control, then hovering does nothing and no tooltip shows up at all. The way to get the tooltip to show up is to move the mouse smoothly, and somewhat slowly, over the control, then pause. As long as the motion is slow enough, the tooltip always shows up. However, if the mouse is then moved, the tooltip goes away, and won't return until the mouse has left the control and come back to it. So basically, First, I will look into showing something on MouseMove rather than Hover, as Hover appears to be inconsistent, at best. Yet that doesn't solve the problem that the tooltip is too inconsistent in behavior. Is there an alternative, or timing property settings for the tooltip that improves responsiveness?
When I double click on a form control while in the design view in a Web Application project within Visual Studio 2010, say a 'button' or a 'submit' for example, it inserts a javascript function into my .aspx file. When I do this at work it automatically creates an event handler for the control in the code-behind.How do I change this to that setting?I don't want to type those event handler subroutines every time!
View 1 RepliesThe title pretty much precisely asks the question, but I shall repeat;
When I double click on a form control while in the design view in a Web Application project within Visual Studio 2010, say a 'button' or a 'submit' for example, it inserts a javascript function into my .aspx file. When I do this at work it automatically creates an event handler for the control in the code-behind.How do I change this to that setting? I have used '/resetsettings' already, and other answers to similar questions do not solve my problem. I have reinstalled, gone through every menu I can find (though I may have missed something)I don't want to type those event handler subroutines every time!
I'm trying to complete this airline reservation application, but having a problem in this part of the question:Creat an event handler for the FlightBindingSource's PositionChanged event: select FlightBindingSource in the class Name combobox then select position changed in method name combobox to creat the FlightBindingSource's PositionChanged event handler. Write a code to access the currently displayed flight object and pass its flightNumber to method DisplayPassengers as a decimal.This Is my code so far:
HTML
Public Class AirlineReservationForm
Private database As New ReservationsDataClassesDataContext()
Private Sub FillAll()[code].....
Below I create an array of labels. I would like to add an click event to my labels. Can someone point me in a direction?
[Code]...
When I utilize AddHandler in VB to add my own method to the Click event :
AddHandler Button.Click, AddressOf myButton_Click
I see that my code executes last - after other event handlers for the Button_Click event. Is there a way to insert my event handler in front of other events so that it executes first?
I ma using DevExpress controls (which doesnt matter for this example). I have a lookupEdit control and I never want the EditValue_Changed event to fire. Can I use RemoveHandler to do this? If so can someone give me a code example of doing this? Should I put RemoveHandler in the load event of the user control I am creating? Or does it go in the EditValue_Changed event of the lookupControl?
View 3 RepliesI want to after clicking on button2,after that if i click on button1 then msg is not displayed Public Class Form1 Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
[Code]...
When I've used the remove handler method in my code, I get this warning:The 'AddressOf' expression has no effect in this context because the method argument to 'AddressOf' requires a relaxed conversion to the delegate type of the event. Assign the 'AddressOf' expression to a variable, and use the variable to add or remove the method as the handler.Why do I have to assign the "AddressOf" expression to a variable?
View 6 RepliesHow to remove a handler set up by a lambda expression? According to this MSDN article, lambda expression should be assigned to variables which should be used to define handler operators. So far, I have used lambda expessions w/o variables.
For instance, the following works:
Private Sub ScaleObjectInit1(ByVal objSrc As NumericUpDown, ByVal objTgt As FrameworkElement) ...
AddHandler Me.upDnScale.ValueChanged, Sub (sender As Object, e As Object) ScaleObject1 (sender, e, objTgt)
End Sub
Private Sub ScaleObject1(ByVal sender As Object, ByVal e As Object, ByVal objTgt As FrameworkElement)
[Code] .....
to know if a control have any handler. I have a dgv and in the editing control Showing event i add an event handler like this: VB AddHandler e.Control.KeyPress, AddressOf Grid_KeyPress_NumbersOnly This event it's added in some of the columns and for the other ones i remove it... The problem it's when the user, for example selects 3 columns where the event it's added, then if the user selects one where the event it's removed, it doesn't remove all handlers... So i have 2 solutions, when removing i put multiple removes or the other check if the event handler it's added doesn't add again. I prefer this second option, but i don't know how to check if the event it's added?
View 3 RepliesIs it possible to determine using VB.NET whether a certain event has any handlers attached to it? I don't own the event, in this particular case I want to know which of the items in a Windows.Forms.MenuStrip have their ToolstripMenuItem.Click event handled.
View 1 RepliesI've been looking for a solution to this for several hours now and cannot find a solution.
The Scenario:I have a masterpage baseclass (called basemaster)All of my master pages inherit from basemaster
basemaster defines an event 'Public Event HandleClickEvent As EventHandler'I have a masterpage named master1
master1 defines an event handler 'Public Shadows Event HandleClickEvent As EventHandler'master1 has a user control named usr1 usr1 has a button that raises event ButtonClicked when clicked I have a page (thePage) that uses master1 thePage has a button click event handler that it registers like so: 'AddHandler Master.HandleClickEvent, AddressOf HandleTheClick' master1 has code something like:
Protected Sub Usr1_ButtonClicked(ByVal sender As Object, ByVal e As System.EventArgs) Handles Usr1.ButtonClicked RaiseEvent HandleClickEvent(sender, e) End Sub when thePage loads I see it register the handler on master1 when the button is clicked, Usr1_ButtonClicked is fired and I step through the RaiseEvent but HandleClickEvent on thePage is never reached.
This code is part of AjaxControlToolkitSampleSite. To be exact, it is in the AsyncFileUpload control[code]...
View 4 Replieshow to add one event handler name clearallboxes that handles the TextChanged event for both examples(Customer text box and Total text box ) This event handler should clear the values in the text boxes that display the results.
View 4 Replies