Does Dispose(disposing As Boolean) Need Implementing For Every Class In A Chain
May 9, 2012
I'm trying to work out whether every Class in an Inheritance chain needs an explicit Dispose(disposing As Boolean) method or, if a given Class has neither managed nor unmanaged resources to dispose of, it can be skipped for that Class - even if a latterClass does require a Dispose method to dispose of mananaged or unmnaged resources?
Here's two examples:
Public Class BaseClass
Inherits Component 'Component has already implemented IDisposable
[code]....
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May 12, 2009
I am trying a example codes of animated graphics. I rewrote all the code and I found an error which doesn't happen on the example code(I run the example project)
error: 'Protected Overrides Sub Dispose(disposing As Boolean)' has multiple definitions with identical signatures.
when I double clicked the error, I got this in Form1.Designer.vb:
'Form overrides dispose to clean up the component list.
<System.Diagnostics.DebuggerNonUserCode()> _
Protected Overrides Sub Dispose(ByVal disposing As Boolean)
[Code]....
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May 30, 2009
Usually, if I make a class that has an implementation and also inherits a class with same method signatures, then I do not need to manually add implementation code. For example, if I create a class that inherits List(of Double) and Implements IList(of Double), then I do not need to add any code to make this compile, since the program realizes that the inheritance covers all the methods of the implementation. (Even though VB will auto-generate methods you can remove them no problem).
Now I'm trying do to something more complicated, using an implementation on top of IList, with a class that has a chain of inheritances, and the program won't accept it. See this example:
Interface ICustomList
Inherits IList(Of Double)
Sub TestSub()
End Interface
Class BaseList
[Code] .....
The final item, CustomList, is not compiling. The program says 'TestSub' must be implemented, but by inheriting BaseList, the class has a TestSub (and it is recognized by intellisense)! All the subs exist, they are functional, so why is the implementation not valid? (I know I can get rid of this error by manually creating an (overloading) TestSub in CustomList and specifying that it is an implementation. However, this should not be necessary since it already exists, and if I am going to be building a chain of classes inheriting each other, this could potentially become time-consuming and annoying.)
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Jun 25, 2012
I looked at the Dispose() method in System.Data.SqlClient.SqlTransaction (using a decompiler):
[Code]....
Why does everyone say in forums that it is Rolling back in the dispose? Where does it rollback?
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Feb 7, 2010
I have a user control that inherits the FW ListView and I need to dispose of two objects when the form's disposing of it's objects. Here's what I've concluded already, am I on the right track?
[Code]...
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May 22, 2010
I am using Visual Basic .Net 2005 professional.From what I understand, I should be disposing of any object that is an unmanaged resource. I understand the best way to tell if a resource is unmanaged is if it has a Dispose method. ie: If I type a dot after my object, intellisense shows .Dispose() as one of the options. If it does, it's an unmanaged resource. Is that correct? In that case, pretty much every control is an unmanaged resource: buttons, forms, panels, etc.In the application I am working on I use an MDIparent container form, which contains MDI children forms, which themselves contain Panels, Menus, Groupboxes, etc, which in turn contain Buttons, Textboxes, Labels, Dropdowns, etc.Do I have to dispose of each button, textbox, label and dropdown within a panel before disposing of the panel?
Do I have to dispose of each panel, menu, and groupbox before disposing of the MDI child form?.Or can I just call the Dispose() method of the MDIchild form and the GarbageCollector will take care of all the controls and resources within the form?Watching the "mem usage" in Windows Task Manager seems to be an unreliable way to detect if I have a memory leak. The numbers just keep climbing and falling (mostly climbing) erratically and without any activity performed on the application. Is there some (relatively) easy way to detect leaks?
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Feb 14, 2010
If I have a class that inherits another class in which there are objects that are disposed in the dispose() procedure, do I use mybase.dispose? ex Class A inherits Class B. [code]
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Oct 28, 2010
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.
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Nov 15, 2010
Consider the following objects:
Public MustInherit Class FileRepository
Public MustOverride Sub SaveStringToFile(ByVal FileText As String, ByVal FilePath As String)
Public Event FileSaved(ByRef sender As Object, ByVal EventArgs As EventArgs)
[code]....
I want my base class to raise the FileSaved event in it's implentation of SaveStringToFile once it's saved the file. However in VB.NET you can't have a derived class raise a base classes event. I suppose I can treat XMLFileRepository_FileSaved as a standard function call and have my SaveStringToFile implementation call it directly?
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Jun 17, 2012
I 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?
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Jun 26, 2009
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?
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Jul 11, 2011
I'm migrating the CenterSnap.cls from its vb version to vb.NET and I'm confused about the following 2 errors after I import the vb6 project to VS 2008.
[Code]...
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Nov 18, 2009
implement singleton in a parent class. Infact what I want is that All the childs etc. should use same instance of the parent.
I have implemented singleton, Changed the scope of parent class's constructor to "Protected". But in the application when ever the new child's constructor is called i.e. "Dim abc as New Ch1()" the constructor of Parent is called (as it is Proctected and can be access from child). Which is undesired behaviour.
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Feb 3, 2011
In 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.
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May 8, 2009
I am having trouble with this project I am working on. I am a beginner to vb and have some background in access databases. I will attach my am doing an inventory project. When you execute the form, a main form pops up that allows you to choose Production or Inventory. My issue is with the Production. In the production form that pops up after clicking Production, there are text boxes to be filled out by the user based on the production run.plementing a class that will give the box count based on the box type entered. I have to use a class based on the project requirements.
Basically to calculate the usage, enter in a random number for Pods Produced, then enter in a box type (which is A box, B box, C box, D box, Master Case). I want the Public Class Box Count in the code to be able to be placed in the production form's main class code and calculate the box count based on the box type entered. If A box, box count should be 50. If B Box, box count should be 100, If any other box is typed in, the box count should be 150
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Jan 27, 2010
I am trying to design a table type structure that contains rows and cells. I intend the cell class to have a value property. I'm trying to work out how I can create a value that can return some defined different types e.g integer, single, date, string. I'd like the cell value to be strongly typed, but I am unsure how best to get this working.
My thinking in code so far:
Public Class Cell
Private _value as object
Public Property Value as Object // How can I define this so that it return a Type
Get // e.g. integer, string, etc
Return _value
[Code] .....
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Oct 21, 2009
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:
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Jun 22, 2011
I have a class that has a destructor and a Dispose method (I also inherit IDisposable). Why is it that the only time my destructor gets called is when I call GC.Collect()?
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Mar 14, 2011
I have a set of nested classes built inside a main class called MainClass. This is a class library project, the end-user will be using the MainClass by referencing.
I want to add a user login functionality at the creation point of the class. So that if the login fails, the entire class is inaccessible to the user. I have the following code
[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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Nov 17, 2009
From what I read it is a good convention to name a method that returns a boolean value with the prefix of "is" or "has". So in keeping with this convention I am trying to name a method in my program with this prefix but I am running Specifically I have a class called Day. It is a simple class with a few data members and one method that returns a boolean value of true or false. The name of the boolean variable is isSpecialDay. This class has a method called isSpecialDay which takes the date of the day, applies some criteria to the date and then sets the variable isSpecialDay to true or false. My problem is that the boolean variable is named isSpecialDay and so it the method. What should I do?
Public Class Day
Private TheDate as String
Private DayName as String
[code].....
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Jun 14, 2009
I have an app that loads a jpg into a picyure box, then updates exif data in exifworks classThe problem is that when I save the image(from image used for picture box) or class (to save exif data) then try to delete, sometimes I get success, others it won't allow delet I have gone to the trouble of using gc.collect, do events, put the delete in a timer & wait for the delete before continuing & still get the problem
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Jun 22, 2010
I am looking for a code snippet which opens a image, creates a clone of this bitmap in memory disposes this opened image so that all handles are closed.
Usually we can open a bitmap using this[code...]
the following code however keeps the Image File locked until the application is running, any suggestions how to dispose it properly. (So that no handle is left open )
Things i already tried: use dispose method of bitmap <= doesnt work (need to write implementation)
Using Block also doesnt work.
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Oct 25, 2011
I have a class Customer which contains the property Extensions which in turn contains the property Any. I tried to do: Dim room = If(customer.Extensions.Any.ElementAt(0).InnerText, Nothing) but it threw an error when it did not find an Extension element in the incoming xml. I thought it would return nothing once it saw that the first expression was Nothing. Do I have to do a multiple if statement in this case?
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Apr 20, 2010
Not sure if I am using the correct term, but it's not child/parent since they aren't nested objects. In my application I've got a User, UserUserGroup, and UserGroup objects which are pretty standard, UserUserGroup is a linking object with corresponding IDs. I am using Linq-to-SQL so unforunately it doesn't used nested objects, but it still knows the relation.
[Code]...
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Feb 25, 2011
I have a query that I cannot seem to replicate in expression method chain syntax. I have two tables "User" and "UserPayment". User and UserPayment have a one to many relation i.e. One User can have many UserPayments.
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Mar 15, 2012
I'm making this POS software for a restaurant and I was wondering what the best way to create the button interface for the items since it's going to use a touch screen monitor.
I was thinking of adding the buttons at runtime to solve the excess space problem, and also add the code at runtime, but that seems like too much work, so I thought I should ask if there are any other ways to approach the problem?
[Code]...
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Feb 22, 2009
I am having an issue with Visual Studio 2008 SP1. Basically, I have a .NET 3.5 solution with a client, shared and server component. While coding, all components run on the same box, but in production the server component is a standalone (remoting) service running on a separate server.
I would expect that a change to the client component would require only a rebuild of that component as there is no client/server dependency. This is in fact how it works on my work PC. However, on my personal PC and another co-worker's PC, any modification - even a simple label change on the client, requires the server component service to be stopped so that the solution can be rebuilt in its entirety. Does anyone know if there is a particular setting that controls this??
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Oct 27, 2011
After Filling a DataTable in GridView's DataSource . A column with check box Type appears but it created as read only column and I can't enable it or make it editable... even i tried .readonly = false and still can't be edited
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Mar 28, 2012
I am indifferent if you are a VB.NET or C# or other .NET developer. I have a FACTORY class like the following:
[Code]...
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