If I have a class that inherits another class in which there are objects that are disposed in the dispose() procedure, do I use mybase.dispose? ex Class A inherits Class B. [code]
View 2 RepliesIf Class X is within the scope of Class Y, is X a subclass of Y?If Class A is a sub Class of B, then is Class B considered a super class of A?if Class C inherits Class D is Class D a superclass or parent of Class C?if Class E extends Class F then we can consider Class E a child of F?if Class G inherits Class H and is within the scope of Class I then who is the parent of Class G? Classes that inherits Class J and classes that are within Class J are all sub classes of Class J?
View 1 RepliesI've been creating short test apps repeatedly to try to understand some of the concepts in VB.NET.For the most part it has been illuminating.I read Bucky's .NET knowlegebase tutorial on passing objects as parameters to newly created forms. He shows how to create a new class that inherits from the base form class and define a New() method with parameters Extending the concept I thought about doing the same thing with a form that was created at design-time (In this case Form2).
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I am trying to create a class in VB.NET which inherits a base abstract class and also implements an interface. The interface declares a string property called Description. The base class contains a string property called Description. The main class inherits the base class and implements the interface. The existence of the Description property in the base class fulfills the interface requirements. This works fine in C# but causes issues in VB.NET.
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I am indifferent if you are a VB.NET or C# or other .NET developer. I have a FACTORY class like the following:
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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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Base class has one field to hold numeric balance value. With 2 methods that accept arguments for adding and subtracting the new input calculating new balance. Sub class has four fields dates, transaction, memo and amount.I have a deposit form, and withdraw form. Each time one transaction is entered it creates an object with sub class fields, then adds to the account collection. My problem is not understanding how to call the deposit/withdraw method and pass the current transaction amount back to the base class to alculate the new balance. Does anyone have any links to information/tutorials on how to perform something like this? As you can see with my code I have tried various different approaches without any success.
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I think I remember reading somewhere that it was possible to assign items to a variable if the item inherited from a base class, but I can't remember how.
I want to have a class that gets properties set and one of the properties is an error code property. I want to assign any exceptions that occur to the property, but it could be any type of exception. I remember that all exceptions inherit from the Exception class.
How can I assign an exception to a property based on the class it inherits from?
I'm extending the ComboBox class in VB.NET and I'm running into a problem prepopulating the collection. I try to do so by using Me.Items.Add() calls in the New() sub. However, once I place the control on a form in the form designer, Visual Studio automatically adds those items to the collection in form designer, then they are added again at runtime. How can I make them only added once?
View 1 RepliesI have a class that inherits from the picturebox class, is represents a gauge. In that class I have an overriden function : [code]and I have on my screen what I expected. But in my form I have a timer that generates a new value for the gauge.[code]For some reason the refresh doesn't work. The gauge doesn't change, the overriden onpaint doesn't get triggerd again. anybody has any idea why?
View 12 Replies[code]The reason that this is a problem is that this is a collection of EventBase objects, but I'm trying to populate it with child classes instead. For example, I might have a JumpEvent class that inherits EventBase, and this is being put into the EventBaseCollection. That means that value.GetType() returns the type of JumpEvent, which as you might guess does not equal the type of EventBase.The goal of course is to simply loop through all of the various events without having to know anything about the sub-classes. Is there a way to determine the type of the base class so that the OnValidate call will work? Or is this just the wrong way to go about it altogether?
View 2 RepliesCan we create objects of a C# class from a VB.NET class and vice versa?
View 2 RepliesI have created 3 classes which inherits from(System.Collections.Specialized.NameObjectCollectionBase)
The first class "SQLCommandsCollection" stores "SQLCommands" in a collection.
The second class "SQLTableNamesCollection" stores "SQLCommandsCollection" objects in its collection.The Third class "SQLDBNamesCollection" stores "SQLTableNamesCollection" objects in its collection.
Ultimately I will sit with a "SQLDBNamesCollection" collection which contains all Table names and its respective SQLCommand objects.
I would like to store this "SQLDBNamesCollection" object in my.settings("QueryViewerQueriesPerTableNamePerDBName")
at runtime but I am unsure what this settings type should be.
I have tried system.oject but this does not seem to work as I get an "Unable to cast object of type 'System.String' to type 'Fusion.SQLTableNamesCollection'" exception when I try to retrieve from settings. See below code.
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When I write the following statement in VB.Net (C# is my normal language), I get an "end of statement expected" referring to the "Implements" statement.
<Serializable()> _
<XmlSchemaProvider("EtgSchema")> _
Public Class SerializeableEntity(Of T As {Class, ISerializable, New}) _
Implements IXmlSerializable, ISerializable
...
End Class
The C# version that I'm trying to emulate is:
[Serializable]
[XmlSchemaProvider("MySchema")]
public class SerializableEntity<T> : IXmlSerializable, ISerializable where T : class, new()
{
....
}
I have quickly made up a class that inherits listboxes and uses
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Sometimes in my web applications I used to get this sort of error, I have no clue why is it coming however if I refresh the page few times the page is loading normally.I am using .net framework 2.0 and visual web developer 2005.
View 1 RepliesI have a window service that Inherits System.ServiceProcess.ServiceBase. While running in debug mode (havent tested compiled), the thread does not see the current user credentials. I need the credentials so I can set up the WebProxy and I would prefer to use the account that service is running under instead of passing the user and pwd as a string.Can someone help me figure out why the code running in the class the inherits from ServiceBase does not have have the credentials of the logged in user?
View 1 RepliesI have a class that has a destructor and a Dispose method (I also inherit IDisposable). Why is it that the only time my destructor gets called is when I call GC.Collect()?
View 2 RepliesI have a set of nested classes built inside a main class called MainClass. This is a class library project, the end-user will be using the MainClass by referencing.
I want to add a user login functionality at the creation point of the class. So that if the login fails, the entire class is inaccessible to the user. I have the following code
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I'm trying to work out whether every Class in an Inheritance chain needs an explicit Dispose(disposing As Boolean) method or, if a given Class has neither managed nor unmanaged resources to dispose of, it can be skipped for that Class - even if a latterClass does require a Dispose method to dispose of mananaged or unmnaged resources?
Here's two examples:
Public Class BaseClass
Inherits Component 'Component has already implemented IDisposable
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I am getting the following Exception when calling MyBase.Dispose ()ObjectDisposedException was unhandled.I tried adding a Try Catch around the call but it doesn't catch the exception.
Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
If disposing Then
If Not (components Is Nothing) Then
components.Dispose()
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FYI: The value of disposing is False
I have a user control that inherits the FW ListView and I need to dispose of two objects when the form's disposing of it's objects. Here's what I've concluded already, am I on the right track?
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I have put this code in the global form Inherits System.Windows.Forms.Form. And then in the form that will inherit this from the global Inherits MenuStrip. "MenuStrip" is what the global form is called. But keep getting this error: Error1Base class 'MenuStrip' specified for class 'Lesson2' cannot be different from the base class 'System.Windows.Forms.Form' of one of its other partial types.
View 5 RepliesI have a class (see below)
Imports Microsoft.VisualBasic
Imports System.Data.SqlClient
Public Class ClientProfile
#Region "Variables"
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It is in the file ClientProfile I have placed in both App_Code and also App_Code/Models
In my code behind I have the following
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The last word, "ClientProfile" has the scary squiggly red line below it. It is not recognizing my class.Even the Intellisense is not picking up te class. Do I have to register the class file in any way?
I've created an add-in for outlook 2010.I have a ribbon that has a button on it. When you click that button, I want it to call a procedure in the ThisAddIn.vb.There are two files: ThisAddin.vb and Ribbon.vb.I've tried several things to no avail. I've also set all the procedures to public.
Call Testing123()
Call ThisAddIn.Testing123()
Etc
How do I properly call this procedure?
****Ribbon1.vb****
Imports Microsoft.Office.Tools.Ribbon
Public Class MyOutlookTab[code].....
I have a main class that has a Sub procedure with no implementation. Any derived class should override and implement this procedure, so I used MustOverride in the base class.
Now, any time this procedure is called, I need to set a specific Boolean variable to True at the beginning of the procedure and set it to False at the end.
Is there a way to avoid writing these two lines of code in procedure implementation of every single derived class? Can I set this value to True in the base class, then run procedure in the derived class and then set the value back in the base class?
I have a sub procedure called ServiceCharge in the CheckingAccount Class now I am trying to call it from the CheckingAccountForm Class but its not cooperating Here is my code I put a bunch of and comments where I want to call the Sub Procedure
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I read some articles about using events and/or class events, but not a single article realy explainend the true use and benefit of using events in classes, but only how to use them.
As far as I understand, you can use an event to trigger a certain procedure of a class within another class or aspx page, but you can do the same by declaring an object of that class and call de procedure or methods directly. why and when or where we would use an event with addhandler to call a routine from a class and not declare an object of the class and call the desired routine directly.
I am trying to call the below from another procedure in another class. The problem is that I am not passing the right parameters on (apparently). What value (and how) do I need to pass on as e?
Public Shared
Sub
DrawFarmFields(ByVal
sender As
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I'm fairly new to the concepts of OO programming - actually programming in general as I am still a student. I'm currently working as an intern in a department that has me coding a new structure that will probably be the base for all their applications to come. So I believe I have the idea behind OO down where you create "basic building blocks" and then expand, expand and expand, until you arrive at the most complex object (for the time being). I need to put all these "advanced" objects into one but how many is too many? Can I have 100 objects inside of this bigger object if it requires all these "parts".I really hope this question makes sense to everyone. I'm sure the answer is not going to be a definite answer either but I just need a rule of thumb to go by. I'd really hate to have 100 objects inside of 1 big one if there is a better design/programming technique. [code]
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