How do I limit an Interface when defining it? What is the correct technical term for what I am describing?For example, I want MyInterface to only be implemented for objects that implement IList(Of T) and ICollection(Of T).
View 5 Repliesi may be misunderstanding this but on MSDN i believe it says that it is good practice to implement the Dispose destructor in every class you write. should i (do you) really implement the IDisposable interface with every class i write? also, is the proper syntax for implementing an interface to put the "Implements" keyword on the line after the "class" declaration? i put it on the same line as "class" and I got an error.when coding the method implemented by the interface, is it mandatory to follow this syntax, as an example: Public Sub Dispose() Implements System. IDisposable. Dispose.
View 3 RepliesI would like to define an interface in the same manner as IDispose. By this I mean that when the interface is implemented it would add functional code.
For example when IDispose is implemented it adds a fully defined Dispose method rather than just an empty sub routine.
Current i'm developing an application track storage of an item.in it abusiness rule says an item can be moved to more than one warehouses. Also i need to keep the history of the Item's history, Thereefore i need to create two entities,"Warehouse" and "ItemsHistoryOfLocations". I have developped an static class diagram to show the relationshop.These are the relationship rules between the classes:
1. A warehouse could be in an Item's History of locations.
2. A warehouse could be in many Items' History of locations.therefore in the forward relationshop -- 1..*
3. In an Item's History of locations, there must be at least one warehouse4. In an Item's history of locations, there can be more than one warehouse
Therefore in teh backward relationship -- 1..* Therefore the relationship betwween teh classes is a M:N. In another Object oriented scripting languaage when ever, and M:N relationship is found between classes, their relationship is slit and put a collection class called "MemberKeyDictionaries" as the bridging entity.But in C# / VB, should we create these collection classe. IF NOT, then how should i modify my class diagram to implement this M:N relationship? and h0w do i implement this M;N relationship in 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.
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I am trying to implement an interface defined in IDL, in a vb.net class here is the idl
interface IEmissaryRoot : IDispatch {
id(0x68030000), propget]
out, retval] IActivityCol** );
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I'm trying to assign a datasource to a ComboBox control during runtime. When I do so, I get the attached message. [Code] I want to learn how to use an Interface. The error message is suggesting using an IList. How would I do this.
View 2 RepliesI have a situation where I am defining an interface and then using that directly eg:Dim x as IWhatever = new implementationOfIWhatever()Which is fine, butmplementationOfIWhatever also implements IDispoable so I want to be able to do x.Dispose or ideally Using x but get the error that that this is not declared or must implement IDispoable as IWhatever of course doesn't define Dispose or implement IDispoable
View 5 RepliesI am trying to implement an interface on an ASP.NET 3.5 web page that will let the user specify up to three conditions for insertion into a Linq to SQL query. It looks something like this:
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how to assemble my query from the values in the various DDLs and TestBoxes.
I have an interface program written in VB .Net (VS2008xxx.dll). Is it possible to implement the Interface in a VB6 program (VB6xxx.exe)?
View 8 RepliesSay I want to know more about a class mshtml.htmlinputelement for example.Say I want to know. What is his parent classes? What interface the class implement? How do I do so through object browser?
View 1 RepliesI have a class which has a variety of details, as follows:
Vehicle Name
Vehicle Address
VEHICLE Percentage: 10
I need to somehow use an Interface for another version, SpecialVehicle.
Special Vehicle has a different Percentage, for example 15.
How can I integrate that in an interface? I just don't understand them?
I downloaded a .net component that I would like to make consumable by COM clients. This component allows one to create a DXF file (Cad drawing). The problem is that the component is composed of quite a few class files, some inherit another. All the examples I found only show one file no namespaces etc. [Code]
View 1 RepliesI think my problem is easy to solve. I developed an interface called "Animal". My programmers created classes for "Dog", "Cat", and "Horse" Later I want to let the user create an animal in a Windows form. How can I get my annimals to appear in the combo for selecting one of them? Each animal has it's own DLL. If tomorrow a new animal is developed, the combo should present the new value.
View 2 Repliesis it possible to implement strategy pattern with different parameters in VB.net? For example I have the following code:
Public Interface InterfaceDataManipulation
Sub updateMyData()
End Interface
How to implemente updateMyData in the class that implements above interface class with different parameter,for example in class x :
Public Class X
Implements InterfaceDataManipulation
Public Sub updateMyData(ByVal x as String)[code]......
But the IDE raises an error "class x must implement updateMyData on interface InterfaceDataManipulation"
I defined the following interface:
Interface INewFileDetector
...
roperty PollIntervalMsec As Integer
[code].....
I need to implement an event interface defined in a COM app so I can get events. I want to use System.Runtime.InteropServices.ComTypes.IConnectionPointContainer. In Adam Nathan's ".NET and COM", Adam shows some C# code that connects to an IE event set. There he does this:
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I am a C# programmer but I have to work with some VB.Net code and I came across a situation where I have two methods on an interface with the same name but different method parameters. When I attempt to implement this interface in a class, VB.Net requires explicitly declaring "Implements MethodName" after the method signature. Since both method names are identical, this is confusing the compiler. Is there a way to get around this sort of problem? I suspect this must be a common occurrence. Any thoughts?
N.B. This was more a case of the programmer not verifying that the interface in question had not changed from underneath him.
Do i have to implement the serial port in the interface again if i have put it in the behind code? Do have any links that can make me understand.
View 8 RepliesAll my data objects implement an interface IFillable
Public Interface IFillable
Sub Fill(ByVal Datareader As Data.IDataReader)
End Interface
In the objects themselves you will typically see something like
Public Class Supplier
Implements IFillable
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Now here is the tricky bit. Given that all my property names WILL ALWAYS match my database column names what I want to do is using reflection generate the fill method at compile time and infer the types and column names for the datareader.I am assuming I will need to structure this functionality as some sort of a tool/vs plugin? What I am looking for is guidance on the best way to go about this.
PS: BTW: Obviously I could easily do this using reflection at runtime but I dont want to take the performance hit for it (Although theoretically if I could cache the values somehow (static class?) it might not be too bad).
Why can't a sub implement an interface and handle event at the same time? The following gives my a syntax error:[code]I know I could handle this kind of logic with another method, but that is not the point. I just want to understand the reasoning behind this.
View 2 RepliesWe have a web service solution in VB .Net 2005 that we have started getting an error in. We provide an interface like the following:
Public Interface IBatchTrackerService
Function InsertBatchTracker(ByVal BatchTrackerObject As BatchTracker, ByRef errorNum As Integer, ByRef errorMsg As String) As Integer
End Interface
In our class we implement this interface with the following code.
Public Class BatchTrackerService
Implements IBatchTrackerService
[code]....
This code was working properly but has now started causing errors. The error we receive is:
Class 'BatchTrackerService' must implement 'Function InsertBatchTracker(BatchTrackerObject As BusinessObjects.BatchTracker, ByRef errorNum As Integer, ByRef errorMsg As String) As Integer' for interface 'IBatchTrackerService'.
The odd thing is that the project compiles correctly, but shows many of these errors after the compile is finished.We recently installed Panda as our virus protection which caused a different error that I found the solution here for.
Updated 4/21/2009 at 11:50 Both the interface and the implementation are within the same project in the solution.
Updated 4/22/2009 at 08:16 I tried removing the BusinessObjects identifier from in front of the BatchTracker type but I still get the same thing. This is just one example of what has happened throughout the entire solution. Every implementation in this BatchTrackerService is flagged as an error, plus there are several other services that have almost every implementation flagged as an error as well. But somehow the project builds successfully, and yes, it runs properly!As for BusinessObjects, it contains many of the classes we use as parameters and it is simply another project within this solution. We do not reference any external assemblies to provide these classes to BusinessObjects.
Updated 4/22/2009 at 08:24 The last thing I noticed was that any function/procedure that doesn't use a 'BusinessObjects' class as a parameter, but simply uses strings, integers, etc is not flagged as an error.
Updated 4/22/2009 at 09:50 I tried reverting back to a previous version and I was able to compile and the error count stayed at zero. I narrowed it down to a check-in of one of the project files where the reference to BusinessObjects was slightly changed. I reverted just this project file and everything compiles fine now.
Recently I needed to compare a suggested pattern for IDisposable and object finalization with the auto-generated one we which VS2005/VB.NET provide. We have used the auto-generated one a fair bit, but after looking it the two side by side I had a number of questions about the VB.NET implementation..
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Overall I am confused by the supposed added value of having an extended code-path that executes when Dispose() is called explicitly(as opposed to having a common path that is executed regardless of whether or not Dispose() was called explicitly). how it does anything other than delay the actual release of managed resources if Dispose() isn't called directly. In essence it seems to only work to make the managed resources unreachable in the object graph, orphaning them until the 2nd GC run rather than freeing them at a point where they are known to be no longer needed.
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 am new to .Net Programming and would like to know if Reflection is suitable for traversing an Object to discover Collections within an instance of a class. I am working with the Microsoft.SqlServer.Management.Smo Namespace.
The plan is to connect to a database, determine what collections exists, then for each of those collections, if the Collection exposes objects which implement the IScriptable Interface, generate a script for the object.How do i do the following (This is pseudo-code as I am seeking assistance with using reflection or some other method to do the following)
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I would like to enumerate all objects in db with one function if possible
So 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.
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I created an interface - TermsService.vb and defined the following method : Function GetTermsList() As List (Of Terms)
how do I modify my TermsDB class to implement the TermsService interface I've just created? Here is my code: Have I implemented it correctly?
Imports System.Data.SqlClient
Friend Class TermsDB
Implements TermsService
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I'm having trouble porting some .NET2-era C# to .NET2-era VB.NET. Specifically, I am trying to define an interface that an ASP.NET user control will implement.(For background, I am trying to re-implement Phil Haack's Model-View-Presenter example from several years ago: http://haacked.com/archive/2006/08/09/ASP.NETSupervisingControllerModelViewPresenterFromSchematicToUnitTestsToCode.aspx)
The C# interface I'm working from defines properties and events (IsPostBack, Load) that are already implemented by the base control.However, VB.NET is forcing me to explicitly implement these properties/events in the user control (Public Property IsPostBack() As Boolean Implements IView.IsPostBack...). I'd like to just define these in the interface and not have to do anything special in the code-behind of the implementing user control.I'm assuming that I can do this in VB.NET, I just don't know how. I've spent all sorts of time googling/bing-ing, and haven't come up with the answer.
I need to create unit testing project for my current website. The currentw ebsite si written in VB. All unit testing examples are using interface to create mock object. My current VB class does not implment any interface. Can I add interface and implement it to my current class and functions without affecting or changing codes to any pages in my website that call the functions? For examples my current class is like:
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Suppose I have piece of code like this:
Public Interface ISomething
....
End Interface
[code]....