At the moment I have the following Command class:
Public Class SubscribeCommand
Implements ICommand
Private ReadOnly _vm As MainWindowViewModel
Public Sub New(ByVal vm As MainWindowViewModel)
_vm = vm
End Sub
[Code]...
In a tutorial i read, you have to implement add {} and remove {} for the canExecuteChanged-Event. But how can i do that, with vb.net?
When editing vb.net forms code in vs2008, how do I select base class events that I want to override? In vs2003 there was a list of overridables in the drop down list but now that list is missing?
View 4 RepliesI'm trying to validate a few things in a form I'm building. It has a datagrid with clients info (taken from an access database) and a few textboxes where the user can type some search criteria. The thing is that those same textboxes are used to add new clients to the database and to modify a client's information if one from the datagrid is selected, so I made it that the buttons to insert and modify clients are disabled on load and thenevery time the text on a textbox changes ("TextChanged" event) they become enabled. So far so good. But then I wanted to make it so when a client from the datagrid is selected both buttons become disabled again until the text on a textbox changes (to make sure they're adding a different client and not the same one that was
selected).
I tried using the CellClick event from the datagrid to disable the buttons, but since every time a client is selected from the datagrid the info is shown on the textboxes, this triggers the TextChanged event too, and the buttons become available.So, is there a way I can tell the TextChanged event not to be triggered when the CellClick event occurs?
I have a WinForms application (OwnerForm) with some UserControl. When textbox of UserControl is changed, I want to filter content of a OwnerForm. But how can I make it? I don't want to specify OwnerForm inside the user control. I know a solution to add manually handlers for MyUserControl.tb.TextChanged to some functions on a owner form, but I think it's bad way. I'll prefer to have overridable functions, but I can't imagine how to do it.
View 5 RepliesI would like to shadow/override an event in VB.NET v2
I need to do it, because I need to implement a interface, let's name it IVisibleChanged, on the custom objects that does not have defined this event, and on the objects that already have defined this event (custom Button, by eg.)[code]...
I would like to shadow/override an event in VB.NET. I do it only because I have to implement in this object an interface, that contains the same event like the base object itself, and I need to keep this base event as is it without modification nor supplementary event additions.How can I do it?
Public Shadows Event VisibleChanged As EventHandler Implements IVisibleChanged
So, I would like to implement a interface that contains VisibleChanged event, but to keep functional the myBase VisibleChanged event too.
[code].....
I have this code that's suppose to override the form closing event, It fires off sucessfully however doesn't prevent the form from closing.
Private Sub Form_Close(ByVal sender As Object, ByVal e As System.ComponentModel.CancelEventArgs) Handles MyBase.Closing
Me.Hide()
e.Cancel = True
End Sub
short question: What's better?
Form KeyDown event vb Private Sub MainForm_KeyDown(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyEventArgs) Handles Me.KeyDown End Sub
Override OnKeyDown
vb Protected Overrides Sub OnKeyDown(ByVal e As System.Windows.Forms.KeyEventArgs) MyBase.OnKeyDown(e) End Sub
Ok, I've been searching all over the web for an answer to this and I'm getting nowhere. I've found several examples and tried code translators, but they either fail to compile at all (syntax is wrong) or fail to solve the problem. Here is what I am up against:
I am trying to implement a service object class for the POS for .NET library using VB9. Specifically, the BillDispenser class. I define my class and inherit from Microsoft.PointOfService.BillDispenser. As normal, it creates stubs for all the MustOverride (abstract) properties and methods that I need to override (I love that), EXCEPT for the DirectIOEvent. Apparently this event is defined as abstract in the POSCommon base class, but VB doesn't generate a stub for it.
No compile errors are generated from not defining it, but I get the following runtime error as soon as my unit test attempts to load the dll[code]...
I have a listview but I would like to add 3 properties (for example one of them is "image") to the listviewitems in it. I was fine with making a custom class with the 3 properties and just inheriting ListViewItem but now I need to use MultiSelect, so it means doing things like(in For Each loops):
ListView1.SelectedItems.Item(i).Image don't work because it returns a ListViewItem not my CustomClass. I could always do : Ctype(ListView1.selectedItems(i), MyCustomClass).Image
But using that over and over again seems like a waste/wrong way to do it?
I'm trying to create a generic Controller Class for generic events. But these these events still need to access their class variable. So my idea is to create the Base Controller Class with a ModelBaseclass variable as _ClassVar, which is inherited by all of the other class Controller classes will derive from. But I want the derived controller classes to override the _ClassVar with whichever one they need.
I want to do this, so the ControllerBaseClass can have all the generic functions that all the Derived Classes would use.
Model :
Public Class ModelBaseClass
Public Overridable Function Foo() As String
Return "Name"
[Code].....
I'm using ASP.Net 2.0. I have a custom control that is inherits from a 3rd-party vendor's control. I'm trying to override the Render method. [code] What I need is that under certain situations I want to be able to render a Button instead of the original control.But I want the Button to have the same client Id as the control so that I can use javascript to manipulate it.How do I assign a clientid to the button?
View 1 RepliesI have to two forms. Form one has several check boxes and when a button is pressed, a second form is opened and certain functions are ran based on which check boxes are selected.The problem is that the second form doesn't show until all of the functions are done.I decided to use the Form's Activated event, which works fine. However, the event fires every time the form comes into focus.Is there anyway to override the event and make it only fire once?
View 1 RepliesBasically, what I want to do is create a new control called EncryptedPictureBox. The image path I would be loading into ImageLocation would be the path of a 512 bit encrypted image. Normally if I load this type of file, it will not display. So I want to override Load() so that I can write the encrypted image to a stream, decrypt it, and then display the stream. I'm trying to save processing time so I don't have to grab the encrypted image, save it to disk as a decrypted image, then display it, then when done, delete the decrypted image from disk.
View 11 RepliesCorrect me if i'm wrong, but i believe most (if not all) classes in the CLR that raise events raise those events from protected methods, for example Form.OnMouseDown... so... In a subclass, when would you want to override the "OnXyzMethod" instead of simple adding an event handler like Visual Studio does by default when you want to handle a controls event?
View 2 RepliesI have a base class, with a const giving its name. If I inherit that class, how can I override the const to give the name of the new class?E.g. (and I know this won't compile!)
Public MustInherit Class BaseClass
Const ClassName="BaseClass"
Public Sub DisplayName
MsgBox(ClassName)
[code]....
What I want is for class One to display its own name, not that of the base class.
Can we override a Public Shared method in derived class? If not why?
View 2 RepliesI want to modify this code or replace it. I want to override the the textbox's textchanged event in a user control.
Protected Overrides Sub OnTextChanged(ByVal e As System.Windows.Forms.ItemChangedEventArgs)
MyBase.OnTextChanged(e)
End Sub
[code]......
I am using Linq to Sql that generated a data contract for a table. I have a date field in that table which is a non-nullable field. I need to override the auto generated property of the date field to return a specific value, something like [code]Is it possible to override an autogenerated property in the designer.vb file using a partial class? I dont want to create a new property as it is currently being accessed in n number of places and I dont want to change it in every place.
View 1 RepliesIs it possible to raise event in one class and handle the event in another class? If so, how?
View 6 RepliesConsider:
Public MustInherit Class Column
Public ReadOnly Property ReturnSomethingUseful() As Object
Get
'return something useful
[code]....
But this gives the following error:
Public Overrides Function ParseValue(sValue As String) As Boolean'
cannot override 'Public Overridable Function ParseValue(sValue As String) As Object'
because they differ by their return types.
I accept that you can't do this, but I'd like to be able to preserve the semantics of what I'm. trying to do, which is to have an untyped version that deals with Object, but a typed version in derived classes that knows about the specific type T.
I have a class that is stored after serialization and compression.Is there any event built in the class that is fired automatically when a class is deserialized and ready to be used??
View 1 RepliesI have a "partial" class in VB.NET. Half of it is auto generated by a code generation tool. That half implements INotifyPropertyChanged, so any properties in that part of the partial class raise the PropertyChanged event.In my "custom" part of the class, I declare another property that depends on one of the properties in the auto-generated side. Therefore, when that auto-generated property changes, I also want to raise a PropertyChanged event on my custom property that depends on it.
If I go into the generated part of the class and raise the event there, that will get overwritten if I ever re-generate that part, so I don't want to do that. I would rather add an event handler in my side of the partial class that checks if the generated property changed, and if so, raise another event for my custom property.
[Code]...
I'm assuming it's because normally you'd use the WithEvents keyword to tell the compiler that you're subscribing to events from that object. I don't have a clue how to do this inside of the class that's actually raising the event, or if that's even possible.
I am having problems trying to get a rowcommand event to fire in a gridview. The code is below.
<asp:GridView ID="GridViewProducts" runat="server" AutoGenerateColumns="False"
BackColor="White" BorderColor="#999999" BorderStyle="Solid" BorderWidth="1px"
CellPadding="5" CellSpacing="1" DataKeyNames="Pkey"
DataSourceID="SqlDataSourceProducts" ForeColor="Black" GridLines="Vertical">
<FooterStyle BackColor="#CCCCCC" />
<PagerSettings PageButtonCount="20" />
[Code] .....
I would like to somehow override the "GotFocus" and "LosFocus" event of the textbox.
Here's the deal. I have big registration form with +- 200 TextBoxes and I want the one that has focus to be highlighter [e.g. let's say change the background color to yellow]. I know, I could write the same code for 200 TextBoxes, but that would be time-killing and I'm really not in favour writing the same thing 200 times as well as with such a huge amount of copy-paste I'm almost sure I would make mistake somewhere.
im making a class.vb which has a sql connection. The class.vb will be used by all forms/windows on the application. So whenever a form needs to access the database, it will call class.vb.
This is the code in class.vb:
Public Sub Openconn()
Dim myConnection As SqlConnection
Dim connstring As String = "Data Source=192.162;Initial Catalog=db1;User Id=sa;Password=1;"
[code]....
but it gives error: value of type sqlconnection cannot converted to array of Sqlconnection.I just want a method that's useful for opening the connection and that is also useful when asigning to a command object.
I'm trying to create Command Buttons dynamically, but clicking the button in question doesn't seem to raise the corresponding CommandButton_Click event. I noticed that in the examples on SO a property is set for Button.OnCommand as well as the CommandName and CommandArgument but it isn't an option in intellisense.(code below without the OnCommand), is it accessed in some other way - if so, why do the examples I've found all show it as .OnCommand?
EDIT: Further to help, I have added the handler however the event is still not firing. The buttons reside in an UpdatePanel and are rebuilt on every postback (along with the handler). I have created a simplified example of what I'm doing which is shown below If the button event fires, it writes "EVENT FIRED" to the txtTestFired Textbox - suffice to say I have never seen that.
.aspx file
<form id="frmMain" runat="server">
<asp:ScriptManager ID="scmAddProducts" runat="server">
</asp:ScriptManager>
[code]....
I have created Command Array like follows.
Public Class Form1
Dim NewButton(25) As Button
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
[code].....
So.. I want to get each and every command button name when I press One of command button.
Ex:
If I press NewButton8 then I need msgbox with it's name, text (All of command button properties if possible). Button Name is very important
I'm rewriting a small application and I'm working on moving the data access logic from the form to a separate class. All was working will when I had all the code in the form. Lets say I had code similar to this in my form:
[Code]...
let's say I have a btnX_click event calling each time when I click btnX:[code] I have menuX menu item and click event for it:[code]I just want every time when menuX item clicked on to do the same thing as btnX control does when clicked.I haven't been programming in VB for ages;Actually haven't been programming at all for a while..But definitely remember writing (calling command event without explicitly clicking on it) this in Delphi; but cannot remember how;
View 4 Replies
