How To Go With Error Handlers
Nov 8, 2011how to go with error handlers. I attempted to code it but I keep getting .net error messages instead of my own msgboxes and such.
[CODE....]
ADVERTISEMENT
VS 2005 Handling Errors In Our Error Handlers?
Jun 30, 2010When we are saving into a txt file the error details there is still a possibility that we will encounter some exception, how should we handle such cases?
View 1 RepliesHow To Use Event Handlers
Jul 11, 2010I 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.
.net - AddHandler Only If No Handlers For Event?
Jan 25, 2010I want to set an event handler only if this is not set:
If GetHandlers(MyWindow.Closed, AddressOf MyWindow_Closed).Length = 0 Then
AddHandler MyWindow.Closed, AddressOf MyWindow_Closed
EndIf
Add An Icon To Shell Handlers?
Apr 30, 2008set the Icon for an item in a shell handler? I've set a contextmenu handler to the extension .savdata and added the text "Open with ConvertFile" to the handler so that the context menu for .savdata looks like this:
Open with ConvertFile
-------------------------------------
Send To >
[code]....
So how can I use "my.computer.registry.HKEY_CLASSES_ROOT" in VB 2008 express edition to add an Icon file path to the left of the context menu handler?
Add Event Handlers To Controls?
Apr 27, 2010I 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?
View 5 RepliesClarification For WithEvents Handlers
Feb 11, 2010When you declare an object 'WithEvents' and then utilize the "Handles" clause at the end of your event methods, how does Visual Basic manage a reference change for the object? In other words, if the withevents var is set to ObjectA, then later I switch it to ObjectB (or nothing), does Visual Basic automatically both remove those handler methods from ObjectA, and attach them to ObjectB? Or do I still have a ObjectA's events being handled behind the scenes?
I ask this because if instead you use AddHandler for an object, and then switch your reference, unless you removed the handler before switching, your original object is still handled (at least I'm pretty sure that's how it works).
Create One Event Many Handlers?
Oct 17, 2009How 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
[code].....
How Many Handlers Are Tied To An Event
Feb 4, 2009how many handlers are tied to an event?
View 2 RepliesHow To Re-connect Event Handlers
Apr 21, 2011I 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
View 10 RepliesRemove All Event Handlers In One Go?
Jul 19, 2009Problem: 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.
VS 2010 - How To Use Event Handlers
Feb 20, 2012I am trying to do sum custom events in a Class. My class listens for a UDP Broadcast, I want to Raise and Event when a message is received to display the message from a windows form.
Here is my code.
Public Class UDP_Broadcast
Public Event NewMessage(ByVal Message As String)
Public Port As Integer = 2456
Public Sub Receiver_Load()
Dim t As New Threading.Thread(AddressOf listen)
[Code] .....
When Do Event Handlers Subscribe
May 19, 2011I 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.
Add Event Handlers For MouseMove And ButtonEnter?
Jun 20, 2012Alright my goal is to test to see if the user has dragged a label over a button. I have add event handlers for MouseMove and ButtonEnter, the trick is that i dont want the buttonEnter sub to fire unless the user is actually dragging a label.Dim dragging As Boolean = False
[Code]...
I thought would work but because the user is dragging the label the mouse never actually enters the button field. I also tried doing lbl.location = button.location... but unless the label and the buttons are the exactly the same size in exactly the same location then the event wont trigger.
Add Event Handlers To A Program Through The Compiler
Oct 7, 2011Isn't the a quick way to add event handlers to a program through the compiler? I'm trying to make a label change color when it's moused over.
View 5 RepliesAsp.net - Define Event Handlers In An Interface?
Nov 12, 2010I am making an interface that has a number of events defined in it. When I implement the interface in a class the events will show up. I want to force a class that implements my interface to also have to make the event handlers too. I don't care where the class raises the event, but I want them to have to define what happens once the event is raised. Is this possible and if so, how do I do it?
View 1 RepliesAvoid Duplicated Event Handlers?
Mar 22, 2011How do I avoid an event from being handled twice (if is the same handler?)
Module Module1
Sub Main()
Dim item As New Item
[Code]....
I want the event manager to detect that this event is already handled by this handler and so it shouldn't rehandle (or readd) it.
Backgroundworker And Objects That Have Event Handlers
Feb 9, 2012I've started working with the backgroundworker class to try and keep the UI responsive while I make some expensive API calls. One of the API classes (details here[msdn.microsoft.com]) has its own event handler which I am using to update a progress bar in a small form that pops up. So I'm looking to use the PublishPackage command in a bgw thread and update a progress bar on the UI thread by using the ProgressHandler method.
[Code]...
Dynamically Creating Event Handlers?
Apr 9, 2010in my project I create buttons dynamically
For i = 0 To btns.Count - 1
btns(i) = New Button()
btns(i).Text = names(i)
btns(i).Size = New Size(btns(i).Text.Length * 15, 25)
[code]....
I need to specify a handler for each button that retrieves the button text how can I do this?
Event Handlers Fail After C# To VB Conversion
Mar 20, 2012Visual Studio 2010 I am trying to learn Caliburn Micro. The sample project is presented in C# only (and runs OK) I have tried several on-line C# to VB converters, without success. Well the conveersion runs without error - - - but the Visual Studio editor chokes on the results. The principal problem seems to be with (what looks to me like) a Lambda. Advanced code conversions are really tough in any case, - but when you do not know C# nearly impossible.
[Code]...
Event Handlers For Controls In An ASP Repeater?
Oct 10, 2011I need to be able to trigger events when a user clicks on a radio button that is generated within an control on my page.I've added an OnSelectedIndexChanged handler to the RadioButtonList and created a function in my code behind that should handle the selection of the RadioButtonList's ListItems, but I don't know how to pass a value to that function.Here's my code:
<asp:Repeater runat="server" ID="rptQuestions">
<HeaderTemplate><table width="100%"></HeaderTemplate>
<ItemTemplate>
[code].....
Event Handlers Processed Asynchronously?
Jun 16, 2009In VB .NET, when you call RaiseEvent X(), is the function that handles the event X processed asynchronously or synchronously. I was under the impression that RaiseEvent and the processing of the event were Synchronous unless created explictly on another thread. I've been told otherwise though.
View 2 RepliesGetting A List Of All Windows Handlers Using The EnumWindows API?
May 4, 2009I understand that I need to use EnumWindows API to get the list of all opened windows (top windows means the main window of each application if I'm not wrong), and get all of the windows handler into a list so I can control each window. I tried to find an example of getting all the handlers using this API but I only found VB6 codes that didn't worked on .Net .If you please can give me an example on how to get all opened windows handlers using this api I would be glad.
View 2 RepliesQuick Clarification About When Have To Remove Handlers In .Net
Aug 6, 2010If I have a class with a couple of event handlers inside of it which are attached to an object that is defined within the class, am I right in thinking that I don't need to implement IDisposable to remove said handlers, even if I explicitly added the handlers myself? Also, can anyone point me in the direction of an article that explains the scope of when it is needed to remove handlers to avoid memory leaks. (I've tried searching many times but I must be screwing up my search terms.)I have a collection; every time an object is added to that collection, I add a handler to a change event of the object.When I'm done with the collection, do I need to go through each item and remove the handler before setting the reference to null?
View 3 RepliesRunning Event Handlers Before Page_load?
Sep 7, 2011I have a problem with running code in the right order. What I am trying to do is updating a session state variable when I press a button. When I run my code it always runs the event handler for the button after my page_load function.The reason why I need to run it after page_load is that, thatI add a line to the textList. Which the loadGui() should add to a table. The table has a remove button for all lines so the loadGui() function can not be added later becuase then the event handler of the remove buttons wont work.
User press the add button which add a row in the TempResponse Session(TempResponse) gets updated loadGui() runs and includes the newly added row
Sub Page_Load()
[code].....
Show Selection Handlers Around The Cell?
Feb 5, 2009when u select any cell in tablelayoutpanel i need to show selection Handlers around the cell. But it's not dispalaying correct way when u select any cell in tablelayoutpanel i need to show selection Handlers around the cell ..But it's not dispalaying correct way..
[Code]...
VS 2008 - Any Way To Unhook Event Handlers?
Apr 2, 2009I have two forms, A and B. A shows B modally. B can exit normally, or can exit because of an exception. Therefore, I have this code in a method in A:
Dim nf as New B
Try
nf.ShowDialog
Catch ex as Exception
'Whatever
End Try
Now, B has some event handlers that handle an event that is raised when a certain value changes. I just found out that if B exits because of an exception, rather than a normal exit, the event handlers are still hooked up. To figure this out, I added a private string variable, and in the constructor of B I added a line to put a GUID.NewGuid.ToString into the variable. When I run this, I can pause in the event handlers I mentioned earlier, and look at the private variable to tell which instance of B is actually handling the event.
Under normal operations, there is only one instance of B. However, if B exits due to an exception, I find that the instance of B which died due to the exception, handles the event before the new instance of B is even created. At a slightly later date, the user presses a button that will cause the event, and, due to something hard to explain, the event gets raised six times, three each from the old, undead, instance of B, and three times from the new, visible, instance of B.
I think that the entire problem I am having is that the event handler is triggering things that cause the two instances to pinball events back and forth between the two of them in a complex recursion. My problem is how to get rid of that undead instance of B so that it stops handling the events that are raised. I tried putting nf.Dispose in the Catch handler of the above snippet, but that did nothing.
VS 2008 Add Event Handlers To Picture Box?
Aug 1, 2009I created a custom class which creates a PictureBox.
The Class looks like this:
Public Class Layer
Dim pb As New PictureBox
Public Sub New(ByVal parentPB As Panel, ByVal parentContex As ContextMenuStrip)
[Code]....
How do I add event handlers to this picture box?
VS 2008 Removing Handlers Associated With A Method?
Jun 8, 2010in my class i have a user defined event and i use the addhandler clause to link the event to a methodAgain this is for a download manager application im working on, and like download managers when u select an item (a download task) from the listview you want its thread log to show and be linked to the thread log so that every time the download task has new information it will be updated directly on the thread log.So addhandler clause worked perfectly for this. But now the problem im having is with removing the handle from previously selected tasks.
i am finding it hard to remove the event handle of the previously selected download task when a new download task gets selected because the previously selected task is variable. I can add a public dimension which corresponds to the previously selected task and that way be able to remove the handler everytime a new job is selected, but it seems abit sloppy to me. Actually i have other events specific to when each thread in a download changes so to remove those handlers i would need an array of the previously selected threads (and that seems even sloppier).
.net - Hooking Up Event Handlers On User Control?
Jul 27, 2011I tried to use this code in the form:
AddHandler MyControl.MouseDown, AddressOf StartDrag
This wont give me an error, but it doesn't happen anything when I mouse down on the Control.
the same doesn't work if I put it in the user control.
Private Sub StartDrag(ByVal sender As Object, ByVal e As MouseEventArgs)
Dim Box = CType(sender, Control)
Box.Tag = New DragInfo(Form.MousePosition, Box.Location)
End Sub