In our current project I am using a generic interface iService which is inherited by all other service interfaces. For instance IService is inherited by ILogService.
The ILogService interface is then implemented by LogService as below:
Public Interface IService(Of T)
Sub Save(ByVal T As IEntity)
Sub Remove(ByVal T As IEntity)
[Code]....
How can I update the method signature so T is displayed as Log?
Is it possible to automatically insert a Code Snippet when an interface is implemented? If so, how do you do it? I am looking for something similar to when you implement IDispoable in VB.[code]This will be used by web forms when transfering parameters from one page to the next using Server.Transfer
View 1 RepliesI am trying to construct a generic interface class with generic functions. My goal was to use this to implement multiple worker classes for database interaction that have the same basic functionality. Each class will deal with different object for example, category, product or supplier but unless the the functions in the interface are generic that this won't work.This is the interface code that I have but I don't know if I have done it correctly. [code]
View 2 RepliesI'm having trouble with the definition of an inherited generic class. I have two base classes that are defined like this:[code]
View 2 RepliesI am trying to create a class implementing the generic IComparer of my own class "Stellungen" (which translates to positions, like on a chess or checkers board).
This is what I got:
Private Class comparer(Of Stellung)
Implements System.Collections.Generic.IComparer(Of Stellung)
Public Function Compare(x As Stellung, y As Stellung) As Integer Implements System.Collections.Generic.IComparer(Of Stellung).Compare
End Function
End Class
Problem is: inside the function I have no access to any fields of my class. If I start off with x. Intellisense will only give me .Equals, .GetHashCode - the methods you get on a type but not on an instance. Visual Studio 10 also highlights this, in the definition of the function the bits "x as Stellung" and "y as Stellung" are written in light blue, meaning it is a type and not an actual object. How do I access the things I want to compare inside my class?
I am creating a generic class that is Implementing IList(Of T) which requires that I implement the GetEnumorator of both IEnumerable(Of T) and IEnumerable. When looking at the members of IList(Of T) I see only one GetEnumorator function, yet it implements IEnumerable(Of T) and IEnumerable. How can I use one function to implement both interfaces when the function definitions only vary by return type?
View 8 RepliesI wrote a serializer (to Byte Array) for dictionaries that have a string key, but an object of some sort as its value.I've never implemented a generic type in a function or used a delegate before, so I'm a bit concerned about this being significantly slower than writing a serialization function for a specific type of Dictionary (Dictionary(Of String, MyClass) for example)Should this code be significantly slower due to the use of the generic type or the delegate?
[code]...
It works, and I could loop it and compare it to a more static Dictionary serializer, but I'm more concerned about when I start using this for a lot of different String/Object dictionary combinations, and it'll take me a long time to write a bunch of static dictionary serializers (that's what I'm hoping to avoid in the first place)edit: simplified intro text
I am writing a COM Add-in for Microsoft Access 2010 using Visual Basic 2010.
I do not understand why the members of an inherited interface are not available to VBA. They do not appear in the VBA Object Browser and a run-time error occurs if an attempt is made to use them.
Here is a full code sample which demonstrates the problem:
First I have a base class with a defined interface:
Public Interface IClassBase
Property id As String
Property Name As String
End Interface
[Code]....
I am working on a plugin architecture and after some reading I have settled on one. The host class will be implemented in C# as well as some of the plugins for that host. The issue I am having is that some of my team uses VB.net. So the question, is it possible to implement a C# (plugin)interface in VB, such that when it is dynamically loaded into the host program it will have the methods required by the interface.
View 1 RepliesI'm currently trying to create a class that is a composition of the SqlDataAdapter class (as unfortunately you can't inherit from it). In order to try and make it as similar as possible I'm using all the same inherits and interfaces as is documented on MSDN.The problem that I am having is that there are some properties where the interface specifies that the type of the property is IDbCommand. But in the SqlDataAdapter the property type is SqlCommand.
View 3 Repliesthis wont be easy to explain clearly but here goes..i have something that works fine in VB but not in C#.i have 2 classes, each class implements a different interface. each interface exposes an Initialize() function that should get called automatically when the plugin loads. since each class has an Initialize() function, i can watch both functions get called in the log. this works fine in VB.
when i do this same thing in C#, only the Initialize() in the first class gets called. anyone have a clue as to why this might be happening?
[Code]...
as you can see the code is identical in both languages. why does it work in VB and not in C#?
I have an interface that I've defined and am working through a bunch classes that will implement it. I'm noticing that in 95% of the implementations, I'm only changing a few lines of the code, so I'd like to know if it's possible to have my IDE generate a block of code inside of a method upon implementation, much the same as implementing IDisposable.not mark my posts as answered. It is extremely rude. You have no idea if you've answered my question.I WILL come back and mark the ones that are answers, as answers.
View 7 RepliesIn some DLL, I have an interface defined like this (shortened code):
Public Interface wsIInvoice
''' <summary>
''' Perform plugin specific actions for a given memberhip invoice that is processedin an incasso batch, and return success result.
[Code].....
The DLL implementing the interface has a reference to the one defining it. And the defining DLL is imported.
I'm doing exactly the same thing in another DLL, and there VS does not complain.
I have to begin saying that I'm working with Visual Basic. The problem is that I have a Entity Framework object and I want to indicate that this object implements a interface, for example:
Public Interface ICatalog
Property created_at() As Date
Property id() As Long
End Interface
Those properties are allready in the object. In c# I've done this just by declaring a partial class of the object and indicates that implements that interface, but in basic is not working, I supouse that is because of the language sintaxis used to declare that a property is implementing some property of the interface, for example:Public Property created_at() As Date Implements ICatalog.created_at
I'm dealing a problem in implementing interface for multiple class.
Assuming I have a class named Class Unu .
I created an interface called Test for those 2 classes.
The first class Unu has 2 data members(i=12 and j=12.17). When you run the program it stores the result on screen 24.17
The second class called Doi has 2 data members(a=20 and b=32.17).
What I want now is to do the same thing for data members a and b so that it stores on screen 20+32.17=52.17
My problem is that I want to be displayed also the result for the 2 data members for the second class on my screen. I implemented the interface on class Doi but I cannot see why he isn't displaying me the second result 52.17.
What I must add to my code to do that?
Here's the full code:
CODE:
I recently wrote an inherited picturebox control. From within the control inside methodI I call Me.Invalidate to fire the control onpaint event. But onPaint does not fire.
View 2 RepliesSo say I define some interface, and that interface has members that need to be implemented under some idea, and I then implement this interface on a class that already has those members defined. How do I NOT receive errors about having to implement said members despite them already being implemented (because I didn't type the oh so ridiculous 'implements IMyInterface.foo').
For example say I have an interface that defines the event KeyPress, and then I have a custom Form that implements this interface of mine. It throws an error. VB is the 5th language I've worked in that uses interfaces... and up until now they've all treated interfaces relatively the same. This is the first time I've seen this not allowed. What perplexes me more, is it IS allowed in other .Net languages. Just not VB.
[Code]...
I frequently use TextBoxes that expect date values. I do a tedious job every time to handle the Validating event. The Validation event ensures that the value is a valid date value according to the current thread's Calendar, and if so, formats the date to "dd-MM-yyyy".
I want a TextBox (e.g. DateTextBox) that automatically runs validation and formats its Text property. All I have to do is dropping it to the form.
I know I should use inheritance; but I do not know where to put the auto-validation code; and I do not know how to save the inherited class as a control in the ToolBox.
I can do this without problem.
Class A
End Class
Class B : Inherit A
End Class
Dim Obj1 As A = New B
I'm trying to create a base interface for a class of mine that uses generics. However, I cannot figure out how to declare a property of the interface when its type won't be defined until the class is initialized.
To clarify, consider List(of T), which according to msdn, implements IList (among other things). Note that IList is not the same as its generic counterpart IList(Of T). So that mean any List(of T) can be converted to IList, which simply returns an object for its items. That's what I want to do with MyClass(of T), be able to cast it as IMyClass regardless of what T is.
But when I try such as:
Interface IMyClass
Prop A as Object
Class MyClass(of T) Implements IMyClass
Prop A as T Implements IMyClass.A
I get a signature error for the last line, even though object is broader than T. What am I doing wrong, or how exactly did Microsoft manage to make List(of T) implement IList?
I have a following code which works fine
MsgBox(AddSomething(Of String)("Hello", "World"))
Public Function AddSomething(Of T)(ByVal FirstValue As T, ByVal SecondValue As T) As String
Return FirstValue.ToString + SecondValue.ToString
[code].....
i've been trying to toy around with generics in vb.net in an example project. At the moment, it looks like this:
I have an interface called IRow (and a class that implements it as a Datarow).
A second interface is ICanGetByRow, which looks like this:
Public Interface ICanGetByRow(Of T)
Function GetByRow(ByVal Row As IRow) As T
End Interface
The function simply takes an IRow and converts it to T. Thats easy enough. Now, for easier access, i want to implement a function in the IRow interface which takes the row and converts it into said ICanGetByRow.
My interface was enhanced by the following function
Function GetObj(Of T As ICanGetByRow(Of T))() As T
You can probably see the problem. If i implemented it like this:
Public Function GetObj(Of T As ICanGetByRow(Of T))() As T Implements IRow.GetObj
Dim foo As New T
foo.GetByRow(Me)
Return foo
End Function
i wouldn't be allowed to construct a new T, and when i tried to make it work by telling the generic function that my interface has a constructor, he wouldn't let me invoke GetByRow anymore.
Public Function GetObj(Of T As New, ICanGetByRow)() As T Implements IRow.GetObj
Dim foo As New T
foo.GetByRow(Me)
Return foo
End Function
how to tell a generic function that it will get a ICanGetByRow(of T) which has a constructor
Suppose I have piece of code like this:
Public Interface ISomething
....
End Interface
[code]....
I want to define a generic interface which will be implemented by an abstract Generic Class. Basically this generic class is a collection class of any class. Interfaces are in a separate project saved as FileReconciliation. Here are the interface definitions
Interfaces
Imports System.Collections
Public Interface ICollectionCommon(Of T As Class)
Inherits IEnumerable
Function Exists(ByVal oKey As Object) As Boolean
[Code] .....
I have a problem when trying to save a picture box image ( I am using vb2008 express edition)When i load my windows form I create a folder called images and the current date (eg images 24062011) using the following code.
Code:
Dim fold As String = "images" & " " & Format(Now(), "ddMMyyyy")
If My.Computer.FileSystem.DirectoryExists("C:usersmickdesktop" & fold) Then
MsgBox(" file exists")
[code].....
this works fine and creates the folder on my desktop. I then load an image into a picturebox and try to save it using the following code which is where the problem starts.
Code:
Dim filename As String = Format(Now(), "ddMMyyyy")
Dim imagename As String = "image"
Dim fileext As String = Drawing.Imaging.ImageFormat.Bmp.ToString
[code].....
so my problem is why does the 1st statement give me the error as surely as I have declared that fold = the folder name then that path should be correct, as the program is set to save the image automatically, not using the savefiledialogue I don't want to have to manually type in the folder name every time I use the program.
I am trying to create bitmap with my text and transformation. I am sure that there is no error in my code. Because this code is worked previously. Here is my code.
[Code]...
In trying to add a bit of usage variety to a generic class I'm working on, I ran into this issue with trying to cast an object into an interface instance where the interface is defined inside the generic class.
[Code]...
We have migrated our Vb6 application to VB.NET using a third party tool. Now we are in a process of Refactoring and introducing object oriented concepts in the application.
In VB6, we were using structures in many places. As a part of introducing object oriented programming,
1. is it a good idea of changing all Structures to Classes? or Is there a concept of "Generic Structure" similar to Generic collections, Generic classes?
2. Can some one guide me any source containing guide lines or best practices for applications that are migrated to VB.NET from VB6 and implementing object oriented programmaing.
I have a base form and I inherit other forms from it. However, if i go back and change say the size of the base form, I don't see those changes take effect in my inherited forms. Does anyone know why that is? Is there a solution to this issue?So as far as design is goes, what exactly gets inherited by other forms?
View 9 RepliesConsider:
Public MustInherit Class Column
Public ReadOnly Property ReturnSomethingUseful() As Object
Get
'return something useful
[code]....
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.