Redeclaring Something In An Inherited Class Is The Recommended-preferred Way To Use "SHADOWS" Or "OVERLOADS"?
Aug 7, 2011
PASTE ALL of this to your Form1 code window please and add one Button to Form1.
Now I am asking developers here who actually do software development for a living
especially those persons holding MCPD or similar Microsoft Certification please.
1) When redeclaring a method as in AnotherClass below which Inherits from ExampleClass,
is the recommnded way to use SHADOWS or OVERLOADS please? 2) What about when you do the same with a PROPERTY please?
Option Strict On
Option Explicit On
Option Infer Off
Public Class Form1
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
[Code]...
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Oct 7, 2011
I have recently come across some code that has the following. First there is a Interface with the following function Function Validate() As Boolean. That interface is then implemented in the an 'ABSTRACT' class like this.
Public MustOverride Overloads Function Validate() As Boolean Implements IBusinessEntity.Validate
Question 1: Why use Overloads in the Abstract class implementation.
Question 2: The Abstract class is then inherited into a class (TestClass). In TestClass the Validate function is implemented as follows Public Overloads Overrides Function Validate() As Boolean. I understand the Overrides keyword is to insure that this is the version of the Validate that you want called and not the Abstract class version but why again use the keyword Overloads?
From what I understand you can overload a constructor of a class by simply changing the constructor signature. Also, you overload Methods and Properties of a class by using the Keyword Overloads. But why do it when your implementing an Interface method, or an Abstract Class method that's inherited.
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Jun 10, 2011
Suppose I have piece of code like this:
Public Interface ISomething
....
End Interface
[code]....
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Sep 25, 2009
I suspect I am being very silly here but I have the following setup
Class MustInherit myBaseClass
'some stuff
End Class
Class myInheritedClassA
[code]....
Running this results in the following error
Unhandled Exception: System.InvalidOperationException:
There was an error generating the XML document. --->
System.InvalidOperationException:
[code]....
is there any way of 'Widening' the inherited class to the base class so this would work?
EDIT:regarding XmlInclude(typeof inheritedClass), currently this method could potentially return a number of types of inherited class (i.e myInheritedClassA and myInheritedClassB) is it case of simply having to add each of the inheritedTypes in this tag?
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Jul 15, 2011
I am inheriting some .net code and they use a couple things i am unfamiliar with and was wondering if someone could shed a little light on why they are used.
Here they are:
Public
Shadows
Sub RemoveAt(ByVal
indextmp As
Integer)
When and why would you use "Shadows"?
Public
Overloads
ReadOnly
Property Count()
As
Integer
When and why would you use "Overloads"?
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Jun 2, 2009
I understand that inherited classes can't be converted from base classes. But is there any way to write a conversion sub, so that the base class gets assigned to MyBase, then extra properties are added?[code]...
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Oct 29, 2009
I'm trying to force an inherited class to use a custom attribute. I'm creating a class library where the user who wants to create an item will do so, but be forced to add an attribute (or visual studio will automatically add the default attribute) to their inherited class. Here is what I'm hoping to achieve:
BaseClass.vb:
<CustomAttribute(10)> _
Public Class BaseClass
End Class
MyClass.vb:
[Code]...
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Jul 31, 2010
i have a class named fdetails and i do not want any other class to inherit from this classCan i set it to not being inherited by another class. I would like to get the things done in the following 3 languages
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May 23, 2010
i have a class named fdetails and i do not want any other class to inherit from this classCan i set it to not being inherited by another class. I would like to get the things done in the following 3 languages
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Jul 5, 2010
bare with me during this silly example. :-) Let's say I have a class like this:
Public Class Animal
Public iLegs as int32 ' Number of legs
Public bWings as Boolean ' Wings? Yes/No
End Class
And another class that inherits the "Animal" class and adds one more property:
Public Class ScaryAnimal
Inherits Animal
Public iScariness as int32 ' 0-100, how scary is it?
End Class
Now, if I have an instance of "Animal" with some values in it, and I decide I want to cast it to a ScaryAnimal for some reason, how do I do that without having to create a new instance of "ScaryAnimal" and copy each property value?Basically I'm looking for a way to do this, without having to write the lines marked with '*** below:
[Code]...
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Oct 14, 2011
I have two classes[code]...
How can I modify class1 in a sub in class2?
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Oct 27, 2009
I placed this checkbox named owner on my form. When i build the project i got the error as
Quote: 'owner' conflicts with property 'owner' in the base class 'Form' and should be declared 'Shadows'
[Code]...
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Feb 1, 2012
I am converting an application from vb.net 2003 to 2005. I got the following warning and need help how to resolve it. withEvents variable 'PreviousPage' conflicts with property 'PreviousPage' in the base class 'Page' and should be declared 'Shadows'
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Jan 26, 2011
Yesterday I started my first DLL project which is for ArabicMessageBox that will allow arabic programmers to display there message in totally Arabic message.My project contain one Form only, and the basic code that I use is:
Public Overridable Function Show(ByVal APrompt As String) As MsgBoxResult
mLoad(APrompt, MsgBoxStyle.OkOnly, "")
Me.ShowDialog()
[code]....
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May 19, 2010
The program below trhows an error in the line "mTable2 = mTable.Copy". The error is: "Unable to cast object of type 'System.Data.DataTable' to type InherintanceQuestion.InheritedTable". This is because mTables is an instance of the InheritedTable class which inherits a DataTable and mTable is a DataTable. So, is there any way I can create the mTable2 to the mTable.copy to the mTable.
Public Class Form1
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
[code].....
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Jan 11, 2010
I'm having trouble with the definition of an inherited generic class. I have two base classes that are defined like this:[code]
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Feb 13, 2010
Is there a way to hide a method of a base class that has been inherited?Lets say the base class has the properties:
x
y
Height
Width
and the method
sub SpecialInstructions()
Now this class is inherited by some classes that either use the SpecialInstructions method or override it. But one class inherits it but cant make use of the method and therefore wants to hide it. I tried shadowing but it still seems that the method is visible ex
Private Shadows Sub SpecialInstructions()
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Dec 30, 2009
I have a class which inherits a form class, and just recently it's started acting strange. All of the controls on the form are locked, and I don't understand why. I can't edit the properties of any controls, or anything.
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Apr 5, 2011
Below is example code of what I want to do:
Public Class Test
Sub New()
Dim cool As New B
cool.Doit()
[code]....
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Feb 29, 2012
When I transfer my project to a server, I now get this error message. What does it mean and how do I fix it?
Server Error in '/HD' Application.
Parser Error
Description: An error occurred during the parsing of a resource required to service this request. Please review the following specific parse error details and modify your source file appropriately.
Parser Error Message: Could not load type 'HD._Default'.
Source Error:
Line 1: <%@ Page Language="vb" AutoEventWireup="false" CodeBehind="Default.aspx.vb" Inherits="HD._Default" %>
Line 2:
[Code]....
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Jul 10, 2009
I am wishing to emulate the auto code generation that happens when you derive from a class, such as Form, and declare the Public Sub New() constructor. When this happens the constructor will auto-generate code like the following:
Public Class MyInheritedForm
Inherits Form
Public Sub New()
[Code].....
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Nov 26, 2010
I have an issue with FxCop and the warning: Abstract types should not have constructors.This is being displayed for a number of abstract classes (possibly all, I haven't checked). When I look most of them have no new method so I assume it's the complier adding a default one. So to remove it I add a private default constuctor (Private Sub New()), this then means all the inherting classes fail to build with the error: Class 'InheritingClass' has no accessible 'Sub New' and cannot be inherited.This seems odd as FxCop requests no public constructor, but when I remove it the build fails.
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Oct 4, 2010
Is there a way to have a class collection of inherited types be initialized? For example, here is my code:
Public Class CamryCar
Property Name As String = "Camry"
Property Color As String
End Class
Public Class RedCamry
[Code] .....
I prefer this one as I don't have an extra property to deal with. But I can find a way to initialize that that list with objects of RedCamry and BlueCamry. Is it impossible or is there another way to do this?
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Jun 7, 2012
I am trying to override a property of a subclass of an inherited base class. I've tried to simplify this code as much as possible but am not comfortable enough with my own abilities to simplify anything else without loosing the ability to understand an answer.The property propertyName in the otherClass is currently incorrect. I want to be able to override propertyName in baseClass with the propertyName in otherClass. Is this possible to accomplish?
Public Interface interfaceName
Interface iInterfacePropertyName
Enum enumName
[code].....
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Apr 1, 2012
[Code]...
Is there an explanation for this limitation? I mean, it's still in the constructor for the object, and the base class constructor is still executed first.
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Apr 15, 2012
I am making some changes to a fairly old project.It has a DataGrid with an Inherited Class
Public Class CustomDataGridTextBox
Inherits DataGridTextBoxColumn
and a Override Sub Protected Overloads Overrides Sub Paint (.......What it was doing was alternating the Data Grid Line colours New Requirement is to break up some items in the DataGrid By categories So I have added new lines to the data and sorted so they show up ad category headers (Production Stations) And they would like the Category Header to be a different colour and then the alternating line colours to restart.This did not sound too difficult but that has proven a trap Setting the category header is no problem but restarting the alternating colours is Previously the row was determined to be odd or even to set the colour.Now I am intending to use an Integer to define what colour is used but it persists only for that text box.
How can I get it to extend its life so each call can refer to it and update it and set the desired colour?All I need to do is have an integer variable that will hold its value for the next call?
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Jan 30, 2009
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:
[Code]....
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Dec 20, 2011
I have a class that exposes an auto implemented property Enabled
[Code]...
But If I had not use an auto implemented property and declared my own backing-field as follows this is accessible from the subclass: Private _Enabled as Boolean ---- EDIT ----
The abve line is incorrect - this is not possible, it was in fact Protected in the original code which allowed access from the sub class See @JonSkeet answer ---- EDIT Of course I can just access Enabled from the sub class to work around this but can someone explain why this is the behaviour?
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Dec 10, 2011
I have a parent class that is also a factory. For example:
Public Class Factory
Public Function clone() as Factory
' Some logic here
[code].....
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Sep 3, 2010
What does this error mean? I havent modified anything in the designer code, but its giving me an error? WithEvents variable 'Move' conflicts with event 'Move' in the base class 'Control' and should be declared 'Shadows'. The error relates to Friend WithEvents Move As System.Windows.Forms.DataGridViewCheckBoxColumn
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