The addhandler function works this way: AddHandler Button1.Clicked, AddressOf Button1_Clicked, However, I have an unknown object: Dim o as Object, But I can't add handler for this object AddHandler o.SomeEvent, AddressOf SomeFunction, How do I add handler for unknown objects as stated above?
View 2 RepliesI have a number of UserControls that have the same event .
When I use an Object instead of UserControl, I can not use Addhandler.
Here is the simplest example of my problem: In this example error is "TextChanged is not an event of Object"
Dim obj As Object = TextBox1 AddHandler obj.TextChanged, AddressOf text_changed_event I have to use this structure, because in a FOR loop I use some different UserControls as obj. All UserControls have the same event.
Is there a way to use this structure without error?
Maybe there is a way to define a new object that covers all my UserControls.
I have a number of UserControls that have the same event .When I use an Object instead of UserControl, I can not use Addhandler.Here is the simplest example of my problem:In this example error is "TextChanged is not an event of Object"
Dim obj As Object = TextBox1
AddHandler obj.TextChanged, AddressOf text_changed_event
I have to use this structure, because in a FOR loop I use some different UserControls as
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I have an ASP.NET page with code-behind in VB.NET. On the ASPX page I have a Repeater with an asp:ImageButton inside the repeater and I want to catch the clicks on the button. As far as I read I have to use FindControl and then handle the copy of the original control:
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I read from a text file to see what I need to add to my MenuStrip. Each line in the text file is a new item. When I read I add the new item's OnClick event using AddHandler to get its text when it's clicked. Here are my two subs[code]....
View 6 RepliesWe are migrating an application from C# to VB to meet our project's needs but stumbled upon a problem with event handling in VB.
The application uses a COM Wrapper access a scanner in Silverlight. The object is created dynamically in the code, and an event is added to "AcquirePage". This requires elevated trust of course.
Code in C#:
dynamic TwainSession;
(...)
TwainSession.AcquirePage += new AcquirePageDelegate(AcquirePageEventHandler);
As the only real "equivalent" of dynamic in VB is Object, we use:
Private TwainSession As Object
Everything is fine up to the point we want to handle an event of this Object. Because we are in Silverlight, we cannot have knowledge of the Object's structure or events, hence the need to create it dynamically. In C# we simply use "+=" to add a handler to an event but:
AddHandler TwainSession.AcquirePage, AddressOf AcquirePageEventHandler
In VB gives: 'AcquirePage' is not an event of 'Object'
I have some code to create dynamic serial port objects, now Im trying to add an event handler to the object so I can capture the dataReceived event. But the vb designer is saying ".datareceived" is not en event of 'object' in this case serialports(dComPortNum)
Public serialports(5) As Object
dComPortNum=1
serialports(dComPortNum) = New SerialPort
[code]....
I am trying to create a Sub that can take an object and add a load of event handlers for it, but the object can be any one of N types that all have these events. How can I do this? If I just have it as an Object as below AddHandler complains that the event does not exist for Object.
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Rather than giving the very specific case (which I did earlier), let me give a general example. Let's say that I have a function, called callingFunction. It has one parameter, called parameter. Parameter is of an unknown type. Let us then say that I wish to copy this parameter, and return it as a new object. For example, in pseudo code, something along the lines of...
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EDIT: Additional Information The first time I posted this question, I received only one response - I felt that perhaps I made the question too specific. I guess I will explain more, I have an ASP page with 10 tables on it. I am trying, using the VB code behind, to come up with a single solution to add new rows to any table. When the user clicks a button, a generic "add row" function should be called.
The difficulty lies in the fact that I have no guarantee of the contents of any table. A new row will have the same contents as the row above it, but given that there are 10 tables, 1 row could contain any number of objects - text boxes, check boxes, etc. So I want to create a generic object, make it of the same type as the row above it, then add it to a new cell, then to a new row, then to the table.
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I want to create a new object of a class which is not predetermined before run-time. Something along the lines of:
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I have the code below giving me grief because it gives unknown error (0x80005000) when trying to add a user to a second group[code]...
View 5 RepliesI'm having some trouble with a program i'm making, everytime i try to run the form that runs this code:
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Beep.tone(1000, note, 240)<< this is the line that throws the exception. i have exactly the same code on my main form and it runs perfectly everywhere else, only in the form where it is supposed to be run do i get an exception. Note array is public and i can access it fine from everywhere else, and the custom class beep works fine.
I have an array of unknown (to the current method) class objects. I do know that each class has a property called "Number". I am trying to write a LINQ query where I am looking for the object with the next Number in sequence. AKA, I'm at Number 8, use a LINQ query to find the object where Number=9.
View 5 RepliesI have a sub that handles when 14 ComboBoxes have their Index changed. I am able to cast the sender of the event, and obtain properties from there. However, after that, I want to be able to change the properties of the actual sender, rather than the cast one.[code]...
View 5 RepliesUsing Access 2003 and VB code, I have created a form with a number of labels. The labels will display an employee's names. I have named the labels name1, name2, name3...etc. Using an ADO data set and DCount I have determined the number of names in an Access table (the number of names can vary). What I want to do is for each record in succession to pick the first name and surname from the data set , combine them into a full name (this part has been successful), and then set the full name into the label caption in succession. Example: full name 1 into name1, full name 2 into name2, full name 3 into name3... until all names appear as labels on the form.
I created a counter to and a variable to increment the label number but when I address the caption property of the variable containing the new label (e.g. name1, name2..etc.) it throws an errer at runtime. Here is the code:
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I have a generic Class I'm using to hold information loaded from a database.I have a method which takes a DataRow as an argument, uses the object's known column name and extracts the data from the DataRow, such that:Dim loadData As T = CType(myDataRow("myColumnName"), T))works as my default assignment in most cases.Unfortunately, due to some horrifying design constraints, some of my columns may be null, and may also be taken from enumerations.This means that when <T> is Nullable(Of SomeEnumeration) the above code does not work because I can't cast 0 directly to SomeEnumeration.Zero.Is there some way to check whether <T> is Nullable(Of [Enum])? Or some way to write a method which allows Integers to be cast to Nullable(Of [Enum])?I feel like I'm forgetting something that would allow me to write one of the other of these, but my weak google-fu is turning up nothing.
EDIT: Okay, thanks to dasblinkenlight's answer below, I can detect when this circumstance is occurring, but what I need to do now is to take a type <T> which I know is Nullable(Of SomeClass), get a type reference to SomeClass and then create a new object of type Nullable(Of SomeClass) and assign that to LoadData.My problem was that I had a lot of difficulty in finding any function which would accept baseType as an actual Type.Parse accepted baseType as a parameter, I knew baseType was an [Enum] type because of dasblinkenlight's code, so I was, in this instance, able to code a solution. It's a solution which is very specific to my problem (i.e., T is Nullable(of SomeEnumeration)), but it's a solution nonetheless.
I can't figure out why my addhandler is not firing?In the Sub "CreateTagStyle" the AddHandler is not firing when the LinkButton is clicked Is there some reason that addhandlers can't be added at certain points of the page lifecycle?
<%@ Page Title="" Language="VB" MasterPageFile="~/_Common/Admin.master" %>
<script runat="server">
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs)
[code]....
My add handler is not correct for some reason. I don't know what I have incorrect. trying to add a row to the datatable upon formload. it says that NewM8_CustomersRow is not an event for BA_TruckingDataSet.M8_CustomersDatatable
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I came across a snippet of C# code which is very useful. I am trying to convert it to VB.NET, but can't seem to.
timer.Tick += delegate { panel.Children.Add(source); timer.Stop(); };
Is it possible to translate this to something similar in VB?
problem with AddHandler with parameters.
i've create a control, here is the code:
Public Class myWorker
Public Event Complete()
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When using a ReadWriteLockSlim for multi-threading support, do I need to EnterWriteLock when using AddHandler? [code]
View 1 RepliesI am creating a dropdown list in code for a gridview. I want to create an addhandler so I can have access to the selectedvalue. However, here (Rowdatabound) the add handler does not get fired off. How should I go about this?
Protected Sub GridView1_RowDataBound(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.GridViewRowEventArgs) Handles GridView1.RowDataBound
''//------------does not fire off add handler-----
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I 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
been banging my head against this problem for days now. Hopefully somebody could point me in the right direction =) I have some button functionality in my Master Page:
Sub Run()
Dim Hbtn As Button = New Button
Hbtn.ID = "hLink"
Hbtn.Text = String.Format("H")
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I am creating a dropdown list in code for a gridview. I want to create an addhandler so I can have access to the selectedvalue. However, here (Rowdatabound) the add handler does not get fired off. How should I go about this?
Protected Sub GridView1_RowDataBound(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.GridViewRowEventArgs) Handles GridView1.RowDataBound
''//------------does not fire off add handler-----
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I have a button in a grid that I created programmatically. The button edits some data in a table using data in a hidden column of the grid that the button is in. Normally I send a hidden field the row data using javascript onclientclick of the button then make the changes to the database using that hidden field. But there must be a way to send the addhandler of the button a parameter. This is the code i have to clarify....
Dim btnedit As New ImageButton
AddHandler btnedit.Click, AddressOf btnedit_Click
btnedit.ImageUrl = "imagesttnEditMini.gif"
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I am comfortable with Vb.Net events and handlers.how to create event handlers in c#, and raise events.
View 4 RepliesI'm trying to add a handler, but as soon as I'm targetting a method that has parameters, the handler fails. This is the simple code:
AddHandler App.Current.RootVisual.MouseLeftButtonUp, RootVisual_MouseLeftButtonUp
Private Sub RootVisual_MouseLeftButtonUp(ByVal sender As Object, ByVal e As MouseButtonEventArgs)
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I'm trying to send values through addHandler. How can I do it.
View 2 RepliesI have the following code to dynamically add handler to my controls
Private Sub HandleMyControls(ByVal Proc As EventHandler)
For Each c As Control In Controls
Select Case IsContainerControl(c)
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There are some subs and functions that help me in what to change and where to loop. My problem is that right now, I can set only .enter event of the control I tried to set parameter as Event but i got an error on that. So, what I want to do is something like this:
Private Sub HandleMyControls(Event as ???????, ByVal Proc As EventHandler)
If MatchControl(c) Then
AddHandler c.Event, Proc
End If