Events Firing Off Unexpectingly More Than Once , Manually Added/removed Event Handlers?
Sep 29, 2009
I'm creating a small game which when the user clicking a menustrip item "New game" adds event handlers to each label in a panel control.
For Each scoreLabel As Label In Me.panelScore.Controls
If Not (scoreLabel.Name = "lblLeftBonus" Or scoreLabel.Name = "lblLeftTotal" _
Or scoreLabel.Name = "lblRightBonus" Or scoreLabel.Name = "lblRightTotal") Then
I'm adding multiple combobox controls to a form dynamically, but am having a problem with one of the event handlers. The first event handler I've added (for the Leave event) fires, but the second (for the TextChanged event) does not. I've tried reversing the order when adding the handlers and I get the same results (TextChanged does not fire). Here's a code snippet for adding the controls, and the code for the events. I've added a breakpoint while testing to verify - but it never hits the code.
Dim cbo As New ComboBox cbo.Name = "cbo" & fldName cbo.Tag = fldName.ToUpper cbo.Top = rowtop cbo.TabIndex = tabOrder cbo.DropDownStyle = ComboBoxStyle.DropDown [Code] .....
When i use my UserControl in a project my Mouse Enter & Leave events aren't firing, i assume i fix this with a raiseevents in my usercontrol. However when i try to do this it says something about "cannot raise base event from derived class".
I have a list view with 2 columns (Prodduct and Price). I want the user to be able to add there own values to the listview and have them save so that they will always stay there.I would also like users to be able to delete specific items from the saved list.
The values added to the colums are paired, and must stay together, as one value would be a product and the other a price, So they must, stay together. as a pair
I am working on a realtime application where the data is addded to a List(of T) all the time. MB per minute
Elements older than X minutes shall be removed from the beginning of the list to free memory.
As far as i can understand will there be an internal (slow) redim when i add each element after i have reach the number defined with the Capasity metod. (I set that quite big from the start, but the data speed is unpredictable so it can be exceed)
What happens each time i remove and element from the beginning of the list , seems like it takes a lot of time, ? new redim ?
What is the most CPU fficient way of removing 1 or many elements from the beginning of such a list?
i am using a Datagridview on my form. It get's it's datasource from a dataset: grd.datasource=set_temp After that I add ComboboxColumns manually. At the end I loop columns and set values into that cells from the comboboxcolumns. Works perfect so far. Now I click on a header and the sorting is changed, and then the cells from the comboboxcolumns all lose their values, they are all empty.
Why and what do I do to avoid that? Or must i refill those manual Values after sorting?
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?
Public Class Form1 Public Event Evt1(ByVal c As c1) Public Event Evt2(ByVal c As c2)
[code]...
However, it seems to be invalid syntax, as the signature of OnEvt1OrEvt2 doesn't match that of Evt2.
Edit: The above code seems to work fine for everyone but me, but it doesn't compile for me in VS2005 SP1.The error message is something like:Error BC31029: The method 'Private Sub OnEvt1OrEvt2(c As WindowsApplication1.c1)' can not handle the event 'Public Event Evt2(c As WindowsApplication1.c2)' because the signatures do not match.
is it allowed to use more than one Sub to handle the same event ? For example , may I have 2 separate subs to handle the Load event of a form ? Will they fight each other ?I have tested it and it seems to work fine , nevertheless I thought I'd ask you . In case you wonder , there is no great deal , I just want to copy the same lines of code in more forms so I am doing it just in favor of the looking aspect .
Eg. ""vb.net" timer event trigger on purpose". This application is meant to run at all times to download a web page every minute. To avoid freezing the UI, I read that the best solution is to move the code from a While/Sleep loop to a Timer that will be triggered every minute. The problem I have, is that the user must wait for a minute before the event is triggered:
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click Timer1.Interval = 60000 Timer1.Enabled = True
[CODE]...
Is it possible to force this event to occur instead of waiting for it?
I have created a simple custom control - we will call it a "panel with buttons". Here is how I instantiate it:
[Code]....
So what I wind up with are multiple instances of my panel. Each of these panels has a button on it called Button1. My question is - how do I capture this button event in a way that I will know which panel index it came from?
In the custom control there is only the Button1_click event - and when I click on it in any of the multiple panels I manually instantiated the event does occur, but how I can tell which one of my instantiated buttons were clicked...
Can you write code to tell an event not to fire? Sometimes in my applications events fire unexpectedly. I know this is a broad question, but it must have happened to others out there.
i have multiple forms in a project and all have statusbar. there is no way to add textbox on status bar but in my previous thread i got the help to add the text box. i created a function in module so that i call that function from all the forms on load and add the textbox on status bar and also add the event on textchange. the function to be called on event change is in individual form (at present)[code]
I'm developing some code to detect new files in a directory and signal it in a new thread through the Created event of FileSystemWatcher. While testing this I noticed that after I removed the eventhandler from the event the thread that was being used was not closed. Why is that? Am I doing something wrong when I'm removing the eventhandler? [code]So first I start off clicking Button 2 to start the event handler. I copy a xml file to the Temp folder and the event will trigger and set the name of the thread. After that I will click Button 1 to remove the event handler. If I then pause the execution the Thread "UpdateSomething" will still be there.
I have a datagridview populated from a dataset datatable and all works well. Changing the values of columns updates the datatable except - if the 1st value changed is the last column on a row, the cellparsing and cellvaluechanged events don't fire. Others may not fire but these two I've been working with. The CellLeaving event fires and the RowLeaving event fires. Going back to the cell and changing the value again does cause the events to fire and everything works fine than.
why the events are not firing the 1st time a value is changed?
In debug I see that the datagridview iscurrentcelldirty value is true and also edit mode.
I have a panel control on a win form, to which I dynamically add a custom control.The custom control inherits UserControls and in the New() sub, I assign the control a GUID.When a control is added to the form, a variable of type List(Of T) holds the details of where i put the control and the size of it.
Within the custom control class there is a delete method. When the method, which deletes the custom control, is run I want the details of that custom control removed.I think I need to use event handlers but I do not know how to handle these when the controls are added dynamically.
I have a windows form that can search for data and the results are results are returned in a Datagridview. The Datagridview is bound to a custom datatable object. On the CellDoubleClick and CellContentDoubleClick events, a new form is supposed to open which will display the results of that row. What I am noticing is that the datagridview doesn't always fire when I immediately double-click on a particular row. It would appear that I have to first click on the row to "select" it, then double-click the row so the event will fire. Is there a way to remove this intermediate "select" step? Is there a property in the Datagridview that needs to be activated so the double-click events will fire right away? Does something possibly need to be done in another DatagridView event?
I have a DGV in VB.Net 2008 connected to an Access DB table. The DGV is not Read Only, but is full of read-only columns except for one, which contains a combo box. The combo box allows the user to select an outcome for that particular row, and then the program copies in a pre calculated value into the "Profit" column depending upon the item selected in the combobox. Then the user hits the Save button and the DB updates (currently via SQL methods in the XSD).
Easy enough so far.
Here is the code.
Private Sub DGUserBets_EditingControlShowing(ByVal sender As Object, ByVal e As System.Windows.Forms.DataGridViewEditingControlShowingEventArgs) Handles DGUserBets.EditingControlShowing
[Code]....
The problem I have is that it would seem that if a user selects the desired outcome from the combobox but does NOT hit Enter, and simply mouses on to a different combobox to again select the outcome for a different row, the first eventhandler is not disconnected and thus the events fire multiple times. This then causes various default MsgBox errors and brings up problems when the user tries to commit all changes to the DB/exit program etc etc.
What do I need to do? Do I need to .EndEdit somewhere appropriate to force the row to save the changes? And where should I call this?
I am trying to programmatically add an unspecified amount of new UserControls to a form. One will be added every time an entry is selected in a ComboBox contained within the UserControl. Problem is, the SelectedIndexChanged event fires completely erratically. Sometimes twice, sometimes 3 times, etc., but never just once. No matter how many times I set the combobox's SelectedIndex to -1, it fires at least once with a SelectedIndex of 0. Sometimes the Itemselected event fires multiple times inbetween SelectedIndexChanged events.
InvoiceEntry.vb snippet: Public Event ItemSelected As EventHandler Private Sub cboItem_SelectedIndexChanged(sender As System.Object, _ e As System.EventArgs) Handles cboItem.SelectedIndexChanged RaiseEvent ItemSelected(Me, EventArgs.Empty) End Sub [Code] .....
I'm trying to use the events Validating and Validated on a ToolStripTextbox.
Private Sub txtMenuOwnIP_Validated(ByVal sender As Object, ByVal e As System.EventArgs) Handles txtMenuOwnIP.Validated MyIP = txtMenuOwnIP.Text StatusLabelIP.Text = MyIP End Sub
[code].....
Neither code is firing.The CausesValidatition of the txtMenuOwnIP is set to true.I can enter stuff into that Textbox and leave it using the Mouse or simply piush Enter, but the posted code won't get fired (used a Breakpoint in both subs). There are no other event routines for this command used.
I have a problem, in Winform or mobile developing, When I newed some buttons in my code(never drew on the form), how can I add the click events to them and use it?
How do I create an event with many handlers. I use the followingo code but it failed. Am I missing something?
Protected Sub myhandler_CheckedChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles CrdCb1.CheckedChanged, CrdCb2.CheckedChanged End Sub
I was editing my code and after deleting a button from a toolstrip vs locked up and trashed the designer.vb code. Now I have all my form code but many of the control objects (e.g. buttons, listviews ..etc) have been deleted. I've re-added the control but none of the events associated with the control (e.g. _click) work. If I delete the event handler code and add a new one the paste in the code it works fine
Problem: I have a document class which contains a list of objects. These objects raise events such as SolutionExpired, DisplayExpired etc. The document needs to respond to this.
Documents can sometimes exchange objects, but a single object should never be 'part' of more than one document.
My document class contains a bunch of methods which serve as event handlers. Whenever an object enters the document, I use AddHandler to set up the events, and whenever an object is removed from the document I use RemoveHandler to undo the damage. However, there are cases where it's difficult to make sure all the steps are properly taken and I might thus end up with rogue event handlers.