Design Patterns - Implement The IDisposable Interface With A Dispose?
Apr 21, 2009
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..
[Code]...
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.
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Jul 19, 2010
i 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.
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Mar 12, 2010
What is the best practice for when to implement IDisposable? Is the best rule of thumb to implement it if you have one managed object in the class, or does it depend if the object was created in the class or just passed in? Should I also do it for classes with no managed objects at all?
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Aug 8, 2011
Background:I have a base class and several inherited derived classes. The derived classes don't always need to have the same properties. If any properties are shared among the derived classes, those properties would live at the base class level ('Contents', for example).Similarly, GoodDocument below has 'GoodThings' but would not want/need to have 'BadThings'.I want to treat instances of both 'GoodDocument' and 'BadDocument' as type 'Document'
public mustinherit class Document
public property Contents as string
public sub new()...
[code]....
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Apr 20, 2009
I am comparing an alternative Dispose pattern to VS2005's default implementation. In doing the comparison I have found several uncertainties with the default pattern which have raised a handful of questions related to sub-class implementations and object Finalization.
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Feb 15, 2010
Class ComponentsContainer ' a component contains other components'
Inherits System.ComponentModel.Component
Private foo as New Component
Private bar as New Component
Protected Override Sub Finalize()
foo.Dispose() ' HERE ? '
bar.Dispose()
MyBase.Finalize()
End Sub
Protected Overrides Sub Dispose(disposing As Boolean)
[Code]...
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Aug 10, 2010
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
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May 18, 2012
I was wondering if I could elicit some tips on how to procede with an interface design approach.That is. What is a good way to go about establishing a "work area" where one can have multiple "floating forms" in this area.Can you have a form which occupies the entire windows desk top and the other forms "float" in this space? the "floating" forms would need to interact with each other where pressing buttons etc on them would affect other forms on the "workspace") Or what would be a good way to start accomplishing that? Or is there a better way to get the same effect?
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Oct 23, 2008
Is there a way to have a form within a program that doesn't dispose when you close it? I have a form in my project and a menu item to show it. When I declare the form globally and show in menuItem.click, then the click event breaks because the form no longer exists. When I declare the form within menuItem.click, then this creates a new form every time I click and that's not what I want.
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Nov 14, 2010
how to implement a classic layout design in vb.net (2.0).The application design is the classical toolbar panel at the top and different panels stacked at the bottom. Depending on the button pressed at the top in the toolbar panel a different panel at the bottom will be available.This is thought to have different part of the software available on different panel but with the toolbar panel always available at the top.To implement this I thought:
1) one tablelayout with 2 rows. First row contain a panel with the button (toolbar panel) and adding/removing hte correct panel requested on the bottom row.
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Aug 7, 2009
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** );
[code]....
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Jul 25, 2010
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.
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Nov 24, 2006
I 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
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Nov 18, 2009
I 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:
[Code].....
how to assemble my query from the values in the various DDLs and TestBoxes.
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Jul 16, 2009
I have an interface program written in VB .Net (VS2008xxx.dll). Is it possible to implement the Interface in a VB6 program (VB6xxx.exe)?
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Dec 23, 2009
Say 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?
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May 6, 2012
i am warsame Essa Mohamed life in Hargeisa Somaliland.
design of vb interface to be the best?
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Jun 7, 2011
is 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"
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Jul 13, 2010
I defined the following interface:
Interface INewFileDetector
...
roperty PollIntervalMsec As Integer
[code].....
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Sep 21, 2011
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:
[Code]...
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Mar 3, 2010
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.
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Jul 30, 2009
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.
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Aug 12, 2009
I am trying to implement a controlling design logic that prompts the user for a length and the area to calculate until he or she enters a number less than zero in the length to end.So far I have it where I believe it�s doing the calculations but it�s not ending when I input a number less than zero or zero.
Sub Main()
' Declare Length As Float
Dim Length As Double
' Declare s, c, t As Float
[code]....
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Jun 11, 2010
How to do interface circuits design to vb.net + using data in excel + autocad
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Mar 11, 2010
I was wondering how such interface designs can be achieved?
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Jan 19, 2011
All 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
[Code]...
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).
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Nov 30, 2010
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).
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Apr 12, 2011
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.
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May 18, 2012
I am getting trouble in designing report. The interface of design and view mode is different. the alignment of the view mode for paragraphs are different from the design.
The following is my design interface:
The following is my view mode:
All the setting are the same, but there has different on it.
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Apr 21, 2009
We 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.
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