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".
View 7 RepliesI am just curious, if there is some way to attach handler to my derived classes base event, if I know EventInfo and I have Delegate to handler function. I have tried MyEvent.AddHandler(CType(Me, BaseClassType), MyDelegate) already, but no positive result at all. Consider being in need of attaching handler to custom event at runtime, while derived class possibly shadows this event.
View 2 RepliesI've created a VB.Net ClassLibrary with a UserControl in it. I can load it from an HTML page and call the methods that I created. This works as expected. I've tried several examples for how to raise an event from the VB code to the js caller, and none of them seem to work (I'm using IE7).
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Supose a base class
Public Class airplane
Private var_num_seats As Integer
Private var_num_engines As Integer
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Obviously, I don't wish that the class Glider has the method "start_engines" neither the property "num_engines". Otherwise, other child classes may have. How can I supress these property and method in child class, not just ignoring (if I can)?
I m trying to raise Click event of Textbox explictly but I m getting "Derived classes cannot raise base classes" error.[code]....
View 1 RepliesI am trying to put an extra event in, UpdateID and it's not firing.
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How do I access the base class inside a derived class?
View 1 RepliesTrying to implement some sort of commit/rollback functionality in my base objects. I have it working with some help from google. However, I have a question My Base Class has a BeginEdit as shown below -
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Now, what I'm confused about is if I create another class, Class1, that inherits the base class. I add some properties such as Name, Age, Location, etc. to Class1.When I do Class1.BeginEdit, wouldn't "Me.memberwiseclone" make a copy of Class1, then CType try to cast it from Class1 to the BaseObject class? How does that work if Class1 has additional properties like the Name, Age..blah blah? Where do those gets stored in the Base class? I'm having a hard time wrapping my head around the concept...
I would like to inherit from the Data.DataColumn in order to produce a DataTextColumn. That means that in the derived class, I dont want to see the non-applicable AutoIncrement property and the like - all I want to see are properties that apply to string types.[code]...
View 5 RepliesI'm struggling here.. I know I can disable the warning manually. However I'm not sure if this would be the right way to go about this.
Here's my interface..vbnet Public Interface IPopulatingClassBase Property Identity() As Int64 ReadOnly Property Dirty() As Boolean Sub Populate_Class(ByVal RecordID As Int64) Sub Save_Class() Sub Reset_Class()End Interface
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PS In my example think of it as classes that populate with data from a database. The parent class would be an organization, and the derived class a location. Both populate and have similar functionality. The only difference is locations are an entity of an organization(the data record for a location constraints it to an organization) upon loading location data I also populate the organization class. This is a real example of what my project does.. so having said I just want to know how I can get around this warning, and if not would it have any consequences if I left it as-is.
i've finally got round to learning about classes and inheritance, but i'm not sure how to proceed. i have a base class Employee, which is inherited by 2 derived classes. how do i use the same Employee class in both derived classes? obviously if i write a sub new for both of them + declare a new Employee class, they won't be using the same class. heres my Employee class:
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I have a usercontrol in my application and inside of this usercontrol I have a declaration:
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Background:I have a base class and several inherited derived classes. The derived classes don't always need to have the same properties. If any properties are shared among the derived classes, those properties would live at the base class level ('Contents', for example).Similarly, GoodDocument below has 'GoodThings' but would not want/need to have 'BadThings'.I want to treat instances of both 'GoodDocument' and 'BadDocument' as type 'Document'
public mustinherit class Document
public property Contents as string
public sub new()...
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I have a base class called PageBase and then a derived class TestPage that inherits from PageBase. In PageBase I have overridden the OnInit() and when it is called and I inspect the value of 'Me', it is of the type of the derived class and not the base class. My question is how does inheritance really work? For instance, when instantiating TestPage does an instance of PageBase get created too?
Here is my code;
Partial Public Class TestPage
Inherits PageBase
Public Sub New()
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Asp.Net 2.0 framewrok - VB.Net application I have a UserControl containing a Asp.Net DropDownList.
Things already researched and or tried:
The control gets bound to data on page load inside if not Page.IsPostBack (only loads once) ID proprety is set for control (ID = ddlMyControl) AutoPostBack is set to true EnableViewState on the control is set to true AutoEventWireUp in the UserControl declaration is set to true EnableEventValidation is set to false in the parent page
The control will not fire it's SelectedIndexChanged event no matter what I do.
I created a little usercontrol that looks similar to Visual Studios toolbox. It works great in the user control project, but when I import it to a form the MouseLeave Event doesn't work. The MouseEnter event works fine however. Any idea why only the MouseLeave event doesnt work? I did notice that I have to use the Panel controls MouseLeave, MouseEnter events for things to work correctly. The Usercontrol Mouseleave and Mouseenter didn't work at all.
Public Class vsStyleToolBox
Public isPinned As Boolean = False
Public isShowing As Boolean = False
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When I do this
Public Class cInherits : Inherits Panel
I get this: Base class 'System.Windows.Forms.Panel' specified for class 'MenuButton' cannot be different from the base class 'System.Windows.Forms.UserControl' of one of its other partial types.
How do I inherit?
I am trying to add shared members in derived classes and use that values in base classes...
I have base
class DBLayer
public shared function GetDetail(byval UIN as integer)
dim StrSql = string.format("select * from {0} where uin = {1}", tablename, uin)
end function
end class
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currently there is error using the tablename variable of derived class in base class but i want to use it i dun know other techniques if other solutions are better then u can post it or u can say how can i make it work? confused...
Well the title pretty well describes my problem. Here is a little bit more detailed description of my problem: I am building an application with a TabControl, which I populate at execution time with TabPages. In my first version of the code, these TabPages were filled with a children ListView. The ListView was also created in code, using AddHandlers to link it to the DragEnter and DragDrop routines. Everything worked very well... Now as I need some other controls on every TabPage, instead of creating every single control in code, I have created a UserControl containing a ListView and a few Buttons, which I instantiate for every new TabPage. The problem now is that the DragDrop event is not raised anymore
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i've a app that starts from a sub in a module, do a few things, and then load the form.
But it doesn't work :/
Here we execute dBase.AddTemporalFilepath
module.vb
Public dBase As New Core.clsDatabase
Public Sub Main()
FurBase.Directory = My.Application.Info.DirectoryPath
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I happen to have these common procedures which I want to be used in my forms and usercontrols, with the form I can put those procedures in the base form which is being inherited but I happen to have a need to use those same procedures in my usercontrols, is there a way that I can have a common base class that I can use both for my form and usercontrol? I haven't used yet a base usercontrol since my usercontrols will not look the same so I have to put those procedures in each one of them and I find it rather cumbersome.
View 8 RepliesConsider:
Public MustInherit Class Column
Public ReadOnly Property ReturnSomethingUseful() As Object
Get
'return something useful
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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.
Consider the following objects:
Public MustInherit Class FileRepository
Public MustOverride Sub SaveStringToFile(ByVal FileText As String, ByVal FilePath As String)
Public Event FileSaved(ByRef sender As Object, ByVal EventArgs As EventArgs)
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I want my base class to raise the FileSaved event in it's implentation of SaveStringToFile once it's saved the file. However in VB.NET you can't have a derived class raise a base classes event. I suppose I can treat XMLFileRepository_FileSaved as a standard function call and have my SaveStringToFile implementation call it directly?
Is it possible to raise event in one class and handle the event in another class? If so, how?
View 6 RepliesI was working on a custom button, in which I had to capture the event of the button, and depending on the certain conditions, either I'll block the event or pass it on the form containing my custom button.[code]Now, I do not have any idea how to block the event and not allow it to pass if the users opts for "No" in the given example.
View 1 RepliesI'm trying to raise an event from a class. It looks ok but it did not raise the event as expected...?
Steps
1 - Load the form2
2 - Boutton1 call the form1 and load the class animation
3 - Class animation raise the event for the form1
Here is the code !
Public Class Form1
Private WithEvents AnimationTextChange As Animation
Public Sub mdiMainEvent_StatusTextChange(ByVal _text As String) Handles
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I have 2 classes one main class called Mygrid and another class inside it called TLBoxEditingControl which inherits a textbox into grid cell.Also I have added one Listbox called LstBox to the usercontrol MyGrid.
1) Initially its visible is false. How can i make visible true in TLBoxEditingControl class.
2) I have an Event called MyList() in Main Class, how can I raise this event in TLBoxEditingControl class.
Here is the code i use, This is not working please expalin
Public Class MyGrid
Inherits DataGridView
Public Event MyList()
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I have added this control to a form and added this code
Private Sub MyGrid1_MyList() Handles MyGrid1.MyList
MsgBox("ggg")
End Sub
Here the event is not raising.
suppose I have the following hirarchy:
Public Class PrimalClass
Public Event SomeEvent()
End Class
Public Class BaseClass
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this code compiles and runs.what I want to do, is remove the event SomeEvent in BaseClass so that DerivedClass won't be able to register a handler to it.
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
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Problem that you may have when dealing with two objects that are raising some events. Here, to make it obvious, I am closing the form, but the problem can be experienced with any other 2 classes event. First, what is the problem !
Let suppose that by pressing a button, you want to raise a custom event, then execute a method and then close the form
In that case, you may use a code similar to this
Event BeepIt()
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
RaiseEvent BeepIt()
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