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.
The 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 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?
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?
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?
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?
How I can hook on my entery tool forms when user press ENTER key to go on next Control which can be any dot.net control which is indexed by TabIndex?My client don't like to use TAB key to jump on next control, they like ENTER as well and we need to refactory all VB 6.0 projects in VB.NET 2005...
Private Sub txtField_KeyPress(Index As Integer, KeyAscii As Integer) If KeyAscii = vbKeyReturn Then
KeyAscii = 0 SendKeys "{TAB}" End If End Sub
Of course above pice of code is just sample code how this is working in VB 6.0... How I can do something like this in VB.NET 2005?
Is 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 Repliesi have a page which dynanically create a link when it load, after i click on the link it should loop in the database fetch all the record and display another set of link , then when i click on these link it should give me all information about this particular record it like this one
Q: when the page loads, it creates the first link which is associated with an event handler, it fire the first event handler (Getname) but it not firing the second event handler (GetnameDetails)
Protected Sub Page_Init(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Init
If ViewState.Item("nameload") IsNot Nothing Then
If ViewState.Item("nameload").ToString = "True" Then
[Code]....
I have a form that is derived from a base class. When the form is created a behavior class is also generated that handles event management, bindings, etc...I create a form instance(FormFoo). When the associated behavior class is created it has a method in it with a signature of: grid_EventA(....) Handles grid.eventA
I want to handle EventA in FormFoo instead of the behavior class so I remove the handler that was generated in the behavior class and add a handler that points to a method in FormFoo. This all works just peachy. The event is properly handled in FormFoo only.
Next I instantiate a modal form(FormBar) via a button click in FormFoo. I then close FormBar. Now we have a problem.When eventA fires it is now handled from the Event handler in FormFoo AND in the behavior class associated with form foo(bad).Is the event handler in the behavior class(grid_EventA(....) Handles grid.eventA) getting resubscribed when the form gets focus again? I don't understand how that event is getting resubscribed.
I figured it out I removed the Handles grid.EventA from the method signature:
grid_EventA(....) Handles grid.eventA
Then I added the handler during initialization of the BehaviorClass using:
AddHandler grid.EventA, AddressOf grid_EventA
Once I did that the problem went away. It appears that when you use MethodName(..) Handles that the event bindings get reset when the control comes back into focus.
In C# I can test for this...
public event EventHandler Trigger;
protected void OnTrigger(EventArgs e)
{
[Code]....
Is there a way to do this in VB.NET? Test for null I mean?
MORE INFO
I forgot to mention. I have classes written in C# but I am writing my unit tests in VB.NET.
I am trying this in the unit test...
If myObject.Trigger IsNot Nothing Then
''#do something
End If
This is causing a compile time error which says ... "Public Event Trigger is an Event and cannot be called directly. Use the RaiseEvent statement to raise an event."
I am trying to convert this code written in C# to VB:[code]This is what I have currently, but it always throws an error when I run it:[code]
View 3 RepliesAt the beginning of a VB .NET function I remove an event handler and add it again at the end of the function because the function's code would trigger those events and I do not want them to trigger for the duration of the function. This usually works, but I have run into a few situations where the event still gets called even though I have already removed it. Sometimes removing it twice at the beginning of the function fixes it, but other times no matter how many times I remove it, it still fires.
Edit:The code is in a Form that has a virtual mode datagridview. I want to run some operations that will trigger the CellValueNeeded event for the datagridview without that event being fired (because it will interfere).
Public Sub DoEventRaisingStuff()
RemoveHandler grid.CellValueNeeded, AddressOf grid_CellValueNeeded
'Do things that would trigger CellValueNeeded
AddHandler grid.CellValueNeeded, AddressOf grid_CellValueNeeded
End Sub
Removing the handler multiple times does not prevent the event from firing, so it doesn't seem to be added multiple times somewhere else by accident.Is there a way to find out what event handlers are active?
I'd like to know how to attach an event handler in VB,There is a C# sample code in this URL that I want to convert to VB (Figure 8)
http://msdn.microsoft.com/msdnmag/issues/06/01/speechinWindowsVista/default.aspx?loc=&fig=true#fig8
I have succesfully converted every lines to VB except those :
[code].....
I have a chart Component that was rendering based on my menu selection(say Sales data, Purchase data), I have two different class to render this, In main form i have a chart control(which was referenced by my appropriate class), When I choose "sales" both sales and purchase chart rendering event handler called, how to solve this?
View 1 RepliesWhy can't I get the clickedItem.SelectedItems.Item(0).Text value?
Dim UserList As New ListView()
AddHandler UserList.MouseDown, AddressOf ToolSearchAD_ListView_Click
UserList.ContextMenuStrip = c_mnuADSearch
[code].....
I have a VB6 app that works correctly in win7.
I downloaded and installed VS2010 yesterday, and converted the app to VB2010.
The app works correctly except for one problem. I have a label array which has two event handlers defined, one for a double click and one for mouse down.
A double click is ignored and the mouse down event is raised. It shows the left button was clicked once.
If I comment out the mouse down handler, the double click event is raised and it shows left button was clicked twice.
What i want to accomplish is allow a user to double click an array element on the screen which then saves the number associated with that element and then click somewhere else to copy the data or alternatively, drag and drop the element to the new location.
The drag operation on the source element always triggers a mouse down, but so does the first of the two clicks in a double click.
It seems that none of the other newer events are raised, eg GiveFeedbackEvent, QueryContinueDrag, DragOver, etc.
So, how do I trap a double click and a drag start without using the mousedown event for the dragstart?