I searched quickly and not find an explicit answer at the following question:Why VB.NET (vs C#) does not "inherit" the constructors with parameters?
Public Class StopLine
Inherits Microsoft.VisualBasic.PowerPacks.LineShape
Public Sub New()
[code].....
Why VB.NET (vs C#) does not "inherit" the constructors with parameters?
Public Class StopLine
Inherits Microsoft.VisualBasic.PowerPacks.LineShape
Public Sub New()
MyBase.New()
[code]....
I am stuck with a problem about generic classes. I am confused how I call the constructor with parameters. [Code] I get error in the starred area of the DBLayer Object. What might be the possible reason? what can I do to fix it? I even want to add New(byval someval as datatype) in IDBObject interface for overloading construction. but it also gives an error? how can i do it? [Code]
View 4 RepliesIn the code below I recieve the compile error "Error Too many arguments to 'Public Sub New()'" on the "Dim TestChild As ChildClass = New ChildClass("c")". I do not recieve it on "TestChild.Method1()" even though they are both on the base class I am inheriting from.
Public Class BaseClass
Public ReadOnly Text As String
Public Sub New(ByVal SetText As String)[code].....
As suggested below but I do not have to do that for Method 1 or other inherited methods and I am looking for the cleanest code possible. This may be a limitation in the system with inheriting parameterized New statements but I can not find it documented anywhere. If it is required then I would like to see the documentation.
I have a base class that contains a fairly large number of parameters in it's New constructor. I have 7 subclasses that inherit the Super base class. My question/issue is, all of the subclasses use the same values for most of the parameters in the New constructor of the base class and these subclasses can be called one after the other. I would like to populate the common values for the superclass and then use those for each of the subclasses, but I can't come up with a good way to do this. If I could figure out how to do this, I wouldn't have to pass all of those parameters in the MyBase.New call for each subclass. I'll try to illustrate with some code .
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In java the constructor is as follows
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can i make 4 constructors with diffrent parameters. now in vb how can i write constructor with parameters.
I have an abstract class which requires a delegate to function. I pass the delegate into the constructor. Now that I have a non default constructor I need to call the abstract class's constructors from the concrete class which means that I need to use MyBase.New(...). I have included a quick example below.
Public MustInherit Class BaseClass
Public Delegate Sub WorkMethod()
Private _Work As WorkMethod
[code]....
I have tried to do this but I keep getting the following error: "Implicit reference to object under construction is not valid when calling another constructor".Can I not do what I am trying to do above? I initially had the delegate setup in its own setter method. But then I am creating a deceptive API because it does require a point to a method to work properly.
what's the rationale behind this limitation: Constructor call is valid only as the first statement in an instance constructor i want to pass an argument to my constructor which validates this argument and calls mybase.new according to this argument but it doesn't let me
example:
Public Class prob
Inherits System.ApplicationException
Public Sub New(ByVal problem As String, ByRef inner_exception As Exception)
[code]....
I'm writing a query to select all records that has any part of parameter. I have one table called Employees. Some people have name like this: John David Clark If the parameter is
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I should be able to get result back as long as there's a match in the parameters. If I use Function Contains (q.FirstName & " " & q.LastName).Contains(employeeName), I will not get any result back if employeeName is "John Clark" Function Contains looks only for next words from left to right. It doesn't match a single word at a time. So that's why I used this in the Linq to SQL:
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I am getting error [07002] the # binded parameters < the # of parameters makers, i checked both parameters were perfect even though i am getting this error here is my code
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Basically Commands has Parameters and parameters has functions like Add, AddWithValue, and etc. In all tutorials i've seen, i usually noticed that they are using Add instead of AddWithValue.
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since it saves my coding time. So which is better to use? Which is safe to use? Does it improves performance?
is there a way to get the GET parameters and POST parameters in just one function or Collection in ASP.NET? Like using $_REQUEST in PHP? I'm using VB.NET.
View 3 Repliesi am just trying to apply inheritance ..Below is my Code ... on which i am not getting the output on my Text_Box ... when in write it in a Child Class
Imports System
Imports System.Windows
Imports System.Windows.Forms
[code]....
Has someone a hint what I'm doing wrong in VB.Net?
Module Module1
Interface ISearch(Of T As ISearchResult)
Function ids() As List(Of T)
End Interface
[CODE]...
The third cast isn't working. Why? did I miss a oop lesson?
What's the choice design that microsoft do that? Of course, as of me, I don't use inheritance a lot, or at all.
View 14 Replieswe have 3 classes:Class S, class A, class B / A and B inherits S.A has a property A1 and B has a property B1.we also have a collection of objects that has A and B objects.ex.
Dim c as Collection = new Collection
c.add(new A)
c.add(new B)
Now we want to make a general object that will read from the collection.
ex .
Dim obj as S
how can we cast obj in order to see properties A1 or B1 according to the class;
Form1
Public Class Form1
Private Sub But_Bell_Click(sender As System.Object, e As System.EventArgs) Handles But_Bell.Click
MessageBox.Show("Ding a ling")
End Sub
[code]....
Where has the whistle button gone? The class part of the inheritance has works because you can access it via code.
I'm facing a problem regarding multiple inheritance in VB.net:As far as I know VB.net does not support multiple inheritance in general but you can reach a kind of multiple inheritance by working with interfaces (using "Implements" instead of "Inherits"):
Public Class ClassName
Implements BaseInterface1, BaseInterface2
End Class
That works fine for classes but I'd like to have an interface inheriting some base interfaces. Something like that:
[Code]...
What are the situations and their associated benefits of using Generics over Inheritance and vice-versa, and how should they be best combined?I'm going to try to state the motivation for this question as best I can:I have a class as shown below:
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Now suppose I have a repository that takes an InformationReturn argument, that has to strore different fields in a DB depending on the type of Info object T is. Is it better to create different repositories each for the type T is; one repository that uses reflection to determine the type; or is there a better way using inheritance capabilities over/with generics?
I have a base class ("MyBaseClass") in a project called "BaseFramework" which is included in several solutions within the company. There are several derived class's in various projects throughout the company that inherit from "MyBaseClass". If I then create a List and add derived class's to it, it will not serialize. I realise that if I were attempting to serialize this list, and the base class and derived class were in the same project, I could simply apply the "XmlInclude" attribute to the base class and include all of the derived class's. This is however not possible across projects, because that would require a circular dependency.
View 1 RepliesHow can I convert following code to VB.NET?
class A
{
public int NumberA { get; set; }
}
[code]....
In VB.NET there is problem with Implements keyword after property declaration. So I need to do something like this:
Class B
Inherits A
Implements IC
[code]....
But there is duplicit misleading property NumberA1.
I have the following code; now i set a propertygrid.selectedobject to the Square object, and start changing the Squares properties. If i change the [Position.x] or [position.y] values in the propertygrid the [Position] and [center] properties update correctly, however when i change the [Center] property, neither [Position] or [Position.x] or [Position.y] update. Is there something else i must do to get this to work both ways. Maybe something is lacking in PointFConverter?
Imports System
Imports System.Collections
Imports System.Drawing
[code]....
Suppose I want to inherit from System.Data.SqlClient.SqlTransaction which is sealed. Supose I want to just put a wrapper around SqlTransaction and always use MyTransaction instead of SqlTransaction. Is there a way I could potentially cast MyTransaction to SqlTransaction using an Implicit/Widening operator?
View 8 RepliesI have a parent class and many children class, right now it look like this:
Public Class Parent
Public Property ID as String
End Class
[Code].....
What I need is a strongly type list List(Of Child) that Inherits from ListOfParent (I need the FindByID method) but I can't find the right syntax.
get around lack of multiple inheritance
View 2 RepliesI am currently working on a framework for applications developed by my company, my boss wants to have a switchboard and a MenuStrip, where the entries and their actions are controlled by a database.
Now I've dealt with all the code to get them working. But the problem that I am facing is that I have duplicated code because each of the classes have the code that deals with ensuring the user has the right privileges and the code to deal with when a user clicks on an item.
Normally I would move this code out into a class and then have each of the classes inherit from the class, but because the switchboard already inherits from the Form class and the customised MenuStrip inherits from the MenuStrip class.After doing some Googling the only answer I have been able to find it using an interface for the functionality, which is obviously not exactly what I want.
Anyway I was just wondering whether any one had any suggestions on what I could do to deal with this problem, as I would like to avoid having duplicate code as much as possible.
I have a library of graphical controls used to display values from a remote device. The controls are typically graphical objects such as a digital meter, analog meter, vertical bar, etc. I first create these controls with a value property. The control will display the value property, e.g. the meter needle will move to the position representing the value.
The next thing I do is to create a new control that inherits the previous discussed control. The new control adds properties that allows the value to be set from values retreived through a communication component. My code that does this is 99% the same for all of the controls. Since I already inherit the graphical control, I can not inherit the class that retreives the values from the communication component.
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I was wondering if it is possible to have dependent types in VB.Net 4, or alternatively, if it is possible to construct inherited objects based on the base class' constructor's parameter(s). For example,
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I'm writing some code in VB.Net which I hope demonstrate to colleagues (not to say familiarise myself a little more) with various design patterns - and I'm having an issue with the FactoryMethod Pattern.
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working on an implementation of a list control for a card game. The catch is the deck control object. I want it to be reusable for different types of cards, which is wheretuck since I seem to be having some issues.First: The basic card object
Public Class BaseCard
'Properties
Private _Id As Integer
[code]....
