I want to create a subclass of a class that has some shared methods. These shared methods all call one specific method. But I can't redefine that specific method in the subclass. If I try to make it overridable in the parent class, it says that shared and overridable can't both be used.
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I have a class like this:
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It works, when I make getBar methods public, but I don't want to expose these unneccessarily. Why I can't call private shared methods from a public one in the same class is over my head. I'm using .net framework 4.0 in a web application.
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...
I am working with a vb program, but there is something strange on one of my .vb code pagewhen i put the "dot" afther the object name its dont show the methods availables for this objectbut on other vb code pages i can see it. but in this one no.for exmaplethis is a piece of code: Dim sb As New StringBuilder()
View 3 RepliesAs a followup to the previous question I have asked "ASP.Net Architecture Specific to Shared/Static functions" I am still struggling to understand the implications of using shared methods in ASP.NET.
So for example let us take the following code.[code...]
I am developing an application that has multiple forms and I wanted to know the best method to have application wide methods and functions. Currently I am using a Module with all my methods that are needed to be used across the entire application in it. However, I read at one point that modules should not be used, as they are only there to preserve backwards compatibility with older VB code. Is there a better way to have methods able to be called anywhere?
View 1 RepliesI Want to know which one is preferred while coding to use Static Methods or normal instances, I prefer to use static if they where few but if there was many of them I start to get some doubts
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if the EmployeeManager Has Many methods (selects deletes updates) is it ok to make them all static.and if it was Normal instance. wouldn't be a drawback if the object is initiated every time specially if GetAllEmployees() is heavily used.What is the better approach to use?
I have a form (frmMain) that contains a custom control (con class). frmMain contains a combo box control and when the user selects a value from it, I pass this value to a sub routine within con class (see red line below). This purpose of the sub routine is to populate a set of comboxes contained in con class according to the value that is passed in.
Private Sub cboGuidelines_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cboGuidelines.SelectedIndexChanged
If bChanged = True Then
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I have a function that 2 derived classes use, but the third doesn't, would it make sense to just leave it in the base class, even though one of the 3 derived classes doesn't use it?The only way I could think of disallowing the third class is to basically create an intermediate class that is derived of the base, then the 2 that use the common function are derived off the second class.
Is it possible to prevent the 3rd class from using the function, while letting the two that are supposed to use it, use it?Does that just seem to go overboard, I mean as long as I don't "try" to call the function from the 3rd class, it shouldn't be a problem, I just was interested if there was a way to prevent it all together without a lot of hassle.
If you can't use Me. in a non-instance method, how would you use properties/functions from a base class in a Shared method?
For example, ClassB inherits from ClassA
ClassB has a Shared Method DoWork();
ClassA has a ReadOnly Property SecurityKey
How do I Public Sub DoWork() Dim test as String = Me.SecurityKey End Sub
I have created a Interface and a couple classes that implement this Interface. I am in the process of developing a Shared Class that utilizes the functions that each of the individual classes have, due to the interface implementation.What i need to know is how do i develop this Shared Class so that way each of the methods within it are restricted to a single data type. This single data type needs to be restricted to any class that has implemented the Interface.
Some examples:
Public Interface IVector(Of T)
Sub Add(ByVal v2 as T)
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As you can see it would allow me to develop one form, since i have standardized the required Subs/Functions for any class the implements the IVector interface. As i am still in developement, i was wondering if my current understanding of the method generics is correct in its current form or what i would have to do to make the Generic Shared Class work in the fashion that i am looking for in the example implementation.
I seem to find more and more that I declare a lot of objects or methods as Shared now but it feels like I am not doing things properly.I try to avoid doing this but then I just end up with situations where I have to create an instance of a class just to call one method that would act no differently if it was just a shared method.Basically I'm just wanting to know if there is any good reason to avoid using Shared objects/methods. Obviously I dont declare EVERYTHING as shared, but it just seems to make things a lot simpler most of the time.For example in my current project (a chat application using WCF) I have a class just called Core which houses a lot of the main functions of the client program, so it has methods such as: SignUserIn, SignUserOut, SendMessage, MessageReceived etc and it also holds properties such as a list that contains all of the currently online users. These things are all declared Shared in my program because as far as I can see there is no reason for having to do this:[code]
View 15 RepliesI have the following class in a .NET class library:
Code:
Public Class JasonTest
Sub New()
End Sub
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The .AddNumbers call works fine, but the AddStrings call yields the error 'Object doesn't support this property or method'.
Is there any way to call a shared method from .NET in VB6? I was unable to find any documentation on this.
I now have a need to dynamically load a dll into my application and I've found the reflection/assembly information and it's fairly easy to implement so I thought I was on my way. However, I quickly found out that I'm only able to use 'shared' methods. What I was originally thinking was I could have one shared method 'library.beginprocess' and then that would make all the necessary calls to the other methods, but this doesn't work unless all the other methods and class level objects are also shared.
I feel like I'm missing something or somethings just going right over my head. I've looked at many, many sites and examples, but I've only run across examples that expose 1 method,[URL]..which explain how to implement a plugin architechture, which I have not tried yet, but maybe would allow me to keep my class structure the same without having to make everything shared?
I want to extend the BitConverter class with an overload of ToString() that takes a parameter of type Char, representing a value delimiter.Why? By default, the ToString() call returns a string representation of a byte array, delimited by dash symbols. The signature does not allow you to specify a different delimiter, which I find very unfortunate.Now because this is not an instance type, or maybe because I'm overloading a shared method, I'm having a hard time finding the proper syntax to define my extension method.What am I doing wrong here, causing the overloads to not show up in IntelliSense:
Imports System.Runtime.CompilerServices
Module BitConverterExtensions
<Extension()>
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I have a List(Of AddlInfo) with AddlInfo being an object. I'm trying to pass addlInfoList by reference into a function of another class:
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This works if I'm not passing the reference into another class, but when I try to do this, I get the following error: Overload resolution failed because no accessible 'Sort' can be called with these arguments:
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What is the purpose of using shared methods that return an instance of a class, as opposed to a constructor?
ie: in VB.net, the system.drawing.color class has shared method "FromArgb(int, int, int) as color". This is different from java's implementation which simply is a constructor that takes three ints. Why the decision to do one or the other?
I'm wondering what will actually change a class, in the sense that serialized objects of this class will no longer be recognized. If the class has reference to shared methods of another class. Will changing such shared methods also change the classes that reference them?
View 3 RepliesSo I implemented my own form of Enum static classes so I can associate strings to enumeration values. One of the shared functions in each enum class, GetValue, is used to quickly look up the string value from an internal array via the offset. While all of the enum classes implement the same exact function, the data types of their parameters differ, specific to the enums in each class.
So I come to a point where I want to create a generic class that can use any of the enums by passing it as a generic type parameter. But I cannot find a way to constrain type T in such a way to be able to call each enum's GetValue function. This is where an interface would come in handy, but VB.NET forbids interfaces for shared methods.
I have a base class that I could constrain to, but the base class doesn't implement the GetValue method, and I can't define a generic version of it, because I need to rely on shared properties of each child class in order for GetValue to do its thing.[code]..
Under component services, a COM+ component is used by the company, right-clicking it and choosing 'Activation' tab will show the 'constructor string' that is used for DB server connection by all applications. How can I access it the simplest way possible?
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Public Class Form1 Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load Dim someproc As Process
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Have a windows application that "got complex" and new products could use many portions of the existing application.Decided to break app into multiple projects to facilitate sharing the appropriate pieces with new products.One object in app provides a library of text phrases used in the production of output docs.Wondering if such an object should be a set of shared methods instead of instantiating it in every object that consumes these text phrases.
View 5 RepliesIn the code below (which I just wrote here - it closely mirrors what my actual code is...) the problem is with the line:
Thing.ThingObject.Add(MyObject)
It says: "Object reference not set to an instance of an object" Yes - it is "nothing" before I try to use the Add method so I must be doing something basic and wrong.The object I am trying to add is fine - I can tell you it is correct, it's just that I apparently cannot use the .add method on the Thing.ThingObject until it is properly created - which I have apparently not done.
Private Sub DoThing()
Dim MyObject as New Object
MyObject = MakeMyObject
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I wonder why it's impossible to create and extension method for Object? I use Excel PIA. The property Cells of Worksheet returns Object (if using with indexes). For example, Worksheet.Cells(1, 1) returns Object type. I know it's a Range object, and I want to cast it to Range. It would be convenient to write following:[code]
View 5 RepliesConsider the following:
Public Module Extensions
<Extension()> _
Public Sub Initialize(ByRef Target as SomeClass, ByVal SomeParam as Something )
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Why is Case 1 failing to initialize the object as expected?
I get an error when I declare an object NOT-shared in a subclass. I can not make this object (glNR) shared.Is there an other way?
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In VB.Net is there any difference between the following three ways of initializing object variables
Method 1
Dim commandObject As SqlCommand
commandObject = New SqlCommand("MadeUpCommand")
Method 2
Dim commandObject As SqlCommand = New SqlCommand("MadeUpCommand")
Method 3
Dim commandObject As New SqlCommand("MadeUpCommand")
Is one more efficient than the others, or are they effectively all the same?
I would like to create a global instance of a User Class that can be referenced by all the forms in my MDI application.This object may be set during the login procedure by the Login form but the user attributes are to be available for other forms. For example, MyUser.ID will be required for meeting the audit requirements whenever data is changed.
View 14 RepliesI have the code as below:
Dim xdTest As XDocument = XDocument.Load(GetXMLPath())
Dim objResult = From xe In xdTest.Elements("Some Element") _
Where xe.Element("strName").Value = strInput _
Select xe.Element("intValue").Value
objResult.
I cannot access any extension methods for objResult, like .ToList() or .First(). The file imports System.Linq and the project is targeted to .NET 3.5. How do I get the extension methods back?
When you type sender. IntelliSense lists 5 methods and yet if you type sender.Left or sender.top these will work. Why don't these properties show up as available for use via IntelliSense.
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